I need a very specific website


Apr 19, 2005
detailing EVERYTHING needed on a 351W swap into a fox, someone whos done it step by step maybe? any help would be appreciated. ive done a search on here and heard about some sticky that isnt there anymore :rolleyes: so if someone could help me out, thanks
  • Sponsors (?)


15 Year Member
Mar 31, 2005
If you have questions post them or pm me.

As far as a complete list of what has to be done and what the alternatives are, that sticky was the only decent collection of info I have seen.

Good Luck


New Member
May 30, 2005
this is form the sticky. this is the main part of it. hope it helps.

The official 351 swap thread.

Information gathered was from ton of research, and actually doing the swap on a serious budget. Keep in mind though, You always spend more than you plan to. Its Murphys Law.

Ok, here we go.


You will ABSOLUTELY need a new oil pan and pick up tube. Sold by FMS through Summit, Part number: FMS-M6675A58 - $131.95

You will ABSOLUTELY need to obtain a 28oz. 157 tooth flywheel and 28oz harmonic balancer. You can find both of these on summit or from pre 1980 mustangs.

You will ABSOLUTELY have to change your intake setup. The 351 intake is wider. If you have a Cobra (gt40) intake or a TFS intake now, both companies sell just a lower intake for the 351 to match the upper intake you already have.

If you want to keep your A/C and power steering you need a new accessory bracket for the 351. FMS also sells this through Summit, Part number: FMS-M8511B351 - $49.95

The 351 will also sit a little higher than the 302 in which 302 headers may not reach the H-pipe. Many companies sell 351 swap headers for this application. I prefer the BBK ones through Summit, Part number: BBK-1511 - $219.95

You may or may not Need a coweled hood. It depends on how tall your intake/carb is, also what motor mounts you use. Most setups dont clear the stock hood, so be prepared to shell out some cash, or to have fun with a dremel.

You will ABSOLUTELY need a new distributor. The distributor is different from a 351 to a 302. You can obtain one from a 5.8 FI truck or from MSD. I believe it might be important to mention weather or not your engine is a rollercam or flat-tappet when ordering the distributor to insure you get the right Distributor gear.

You will ABSOLUTELY need a spacer for the crank pulley for proper alignment of the belts. FMS sells this crank spacer through Summit, Part number: FMS-M8510B351 - $34.95

You will ABSOLUTELY Have to drill your existing 302 heads. The reason for this is that the headbolts on a 351w are larger. Some newer aftermarket heads are predrilled for the 351, but most are not. This is not a difficult task. You simply need to drill out your existing headbolts to be a small amount larger. Take a 351 headbolt with you when your drilling so you dont Overdrill.

The swap requires all sorts of little miniscule items which you will need to get for your personal application. These items may/maynot include kickdown cables, Accelerator cables, Larger Headbolts, Throttle brackets, etc..
These items are not listed in individual categories because autozone carries all of these parts in stock. Just bring in what you need for your application.
And what I mean by application is that if I give a certain part # for MY holley carb throttle bracket, it will not neccesarily work on YOUR edelbrock. If you cant figure out what parts you need for these items, You are not qualified to be doing the swap.

If a part was not mentioned, it means it is not required for the swap. Yes its nice to have subframe connectors, and while most people will argue its a neccesity for this much power, it is not required. When doing the swap you can do many things on a budget (as I did) But remember to get the overlooked parts in conjunction with your new power.

Yes, having a 351w block is a prerequisite for the swap, do not forget this step! lol

Now, for those money saving tips

Using stock AC/PS Bracket
I was able to use the stock bracket, simply by using very large washers and various spacers. You just need a large selection of washers, You torque them down enough and you can get them to hold it just as securely as the FMS bracket. (pics below)

Using stock headers
Headers. If your cheap you dont need to get new headers. The stock shorty headers CAN be used. (I am living proof) All you need to do is hammer the tube on the drivers side nearest the steering knuckle. It will be tight, but it definitely can be done. You will also need to modify your H-Pipe. The way I did mine was I cut my collectors off the Hpipe, and bolted them to the headers. Then, I welded a pipe from the collectors back to the Hpipe. Would cost a max of 30$ at any local muffler shop to do. THIS WORKS. YOU DO NOT NEED AFTERMARKET HEADERS (although I reccomend you get them if you have the cash)

Aftermarket Headers for a 302 in regards to swap:
Havent tryed installing longtubes onto a 351w, But I would put money on the fact that it would not work without SERIOUS Modifications. The stock headers BARELY fit, so attempting to use non-swap longtubes will most likely be a loss.
I have seen other typical shortie aftermarket headers however make the jump into a 351 with NO modification to the headers at all. Apparently aftermarket headers fit in nicely. Just keep in mind that if you dont buy proper swap headers, you will HAVE to modify your Hpipe, Making it impossible to upgrade to swap headers in the future, But allowing you to use any 302 style shortie header that is for a non swap function.
Let me clear this up so everyone can understand easily.
long tubes - Not worth the time labor to install
stock - some header modifications neccesary, but works great
aftermarket shorties - most fit like a glove, Remember you must mod Hpipe tho

Getting stock Gauges to work when going carbed:
They will work fine as long as you dont cut any wires. I know its tempting to remove all those ugly looking ECU wires, But leave them untouched untill the end. When your done with your engine swap, Just reattach the sensors into there respected locations on your intake.

Fuel Pump for carb:
Everyone says you have to get a new fuel line pickup and all this nonsense.
Let me clear some things up here. I have not tryed using the EFI pump with a regulator but it HAS been done succesfully. You will need a return line going back into the tank though, or pressure will creep up on you when your idleing.
I used a holley blue out-of-tank pump. To do this, Just remove the EFI pump from the tank (drop the fuel tank) And place a tube in place of the EFI pump. You are now using your existing pickup without the 130$ pricetag.

Electric Fan:
For some reason, My clutch fan stopped working, This is a excellent time to upgrade anyways.
See http://www.mustangmonthly.com/howto/11879/
Also, Go get a 3G alternator.

A final note:
You should realise that in most instances, when people are going to a 351 platform, They tend to add other performance parts with it. Keep in mind how much HP/TQ you are realisticlly putting to the ground, and remember to consider the outcome if you put over 350 WHP to your tranny on a launch.
This is here to server as a informative dish for the engine side of the swap, and may develop into more. If you plan on doing this swap right, You should absolutely have subframe connectors, a stronger rear end, and a upgraded transmission. Just be prepared to break more things. They dont call it fix or repair daily for nothing.

Here are some other part #'s
Oil Pan - Ford Racing P/N M-6675-A58
Oil Drive - Ford Racing P/N M-6605-A341
Flywheel - Ford Racing P/N M-6375-A302
Harmonic Balancer - Ford Racing P/N M-6316-C351
Crankshaft Pulley Spacer - M-8510-B351

351w Swap Info.

Written by: Mat Peirce aka MAT88GT

This is an ongoing article and will be updated frequently. If you would like to see more questions answered feel free to contact me

Will it fit?

The deck height of a 351w is 9.480" for 1969-1970 blocks and 9.503" for 1971 and up blocks compared to the 8.2" deck height of the 302w block. This equates to a taller and wider motor. There have been many people who have squeezed 351's under the stock Mustang hood, but chances are at least a 1.5" cowl hood will be needed for the 351w combination. The motor mounts on 351w and 302w blocks are interchangeable.
Can I reuse any 302w parts on the 351w?

There are many interchangeable parts between the Windsor blocks. The 351w uses a wider intake than the 302w, but you can use a cobra upper with a 351w specific lower intake. Timing covers, water pumps, and several of the accessory brackets are interchangeable. You do need a FMS power steering and a/c bracket in most cases. Cylinder heads from a 302 can be used on a 351w block by drilling the head boltholes to accommodate the larger 1/2" 351w head bolts. The 302w fuel rail can be modified to fit the 351w by extending the rail crossover tube.
Will my 302w balancer work on my 351w?

The 351w uses a 28oz/in imbalance that is the same as early 302's. You can use a 28oz/in 302 balancer on the 351w.
What is needed to use the serpentine belt setup from a 302 on a 351w?

The 302 alternator bracket can be utilized on the 351w, along with the reverse rotation water pump along with the air conditioning and power steering brackets. The crank pulley requires a 3/8" spacer available from FRPP between it and the balancer for proper pulley alignment.
What do I need for exhaust on the 351w?

Swap headers are a must for a proper 351w installation. There are many suppliers of 351w swap headers and matching intermediate pipes including: Hooker Headers, Hedman, BBK, Mac, and Kooks. Most 351's will benefit from a 1 3/4" primary tube size.
What parts are a must have for a 351w installation?

First, you need an oil pan and matching pickup to mount the 351w into the Mustang that will clear the K-member. Moroso, Miloden, Canton, and FRPP all make exceptional 351w Mustang swap oil pans. Note that the FRPP version is a 5-quart capacity design while the others are 7 quarts. Crown Vicorias and Grand Marquis also have a dual sump 5-quart oil pan that will fit the Mustang K-member. Second, an intake is needed. If you are using EFI Edelbrock and TFS make intakes for EFI equipped 351's. You can also use a FRPP Cobra upper with a matching lower, or a 351w truck lower with stock EFI Mustang upper. For carbureted applications there are many companies making 351w carburetor intakes such as: Edelbrock, Holley, Weiand, and Offenhouser. You will need a 351w specific distributor. MSD and EFI equipped 351w Thick Film Ignition distributors will work with the Ford EFI EEC. Any points, Duraspark, or MSD distributor will work with a carbureted combination.
What block should I use?

All pre 1994 factory 351w blocks are non-roller designs. Blocks produced before the early 1980's used a two-piece rear main seal. Ford trucks and vans produced after the mid 70's use a stronger rod design often referred to as 'Football' rods because of their football shaped bolt heads. 1969-1970 blocks had a lower deck height (9.480") and provide more compression from the factory. These early blocks also have a stronger thick wall casting design and are often thought of as the strongest factory 351w block. Keep in mind that all 351w blocks are considerable stronger than the factory 302w block. If you need an exceptionably strong 351w block design FRPP and Dart both offer aftermarket 351w blocks in many varieties.
How do I install a roller cam in my 351w?

The easiest way to use a roller cam in the 351w is to find a F4TE casting number block from 1994 and later F-series trucks and E-series vans. If you happen to have a block produced before 1994 you can retrofit a roller cam quite easily. The first option is using 5.0L hydraulic roller lifters, retention spider, and lifter link bars with a reduced base circle hydraulic roller camshaft. This method requires machining the lifter valley to accept the spider bolts. Second, Comp, Crane, and Crower make retrofit roller lifter that will allow the use of any off the shelf 5.0L style hydraulic roller cam to be used in a non-roller 351w block. Any flat tappet 351w-302w flat tappet camshafts will work with the correct corresponding firing order.
What vehicles should I get my 351w from at a junkyard?

Ford produced many vehicles which used 351w motors including, but not limited to, the following... Mustangs Fairlanes Galaxies Cyclones Torinos LTD's Crown Victorias Grand Marquis Rancheros Cougars F-series trucks E-series vans Broncos
What about a fuel system?

The 351w is defiantly going to consume fuel at a higher rate than a smaller motor and you should upgrade the stock fuel system to provide for this thirst. EFI equipped Mustangs should use at least a 190lph in tank fuel pump and 24+ pound injectors. Many carbureted Mustangs use a Holley Blue pump or equivalent, which requires slight modifications to the stock in tank fuel pick-up to function properly. An adjustable fuel pressure regulator should be utilized with both EFI and carbed systems.

To help you identify your engine, both the 302 and the 351W have six valve cover bolts. The 351C, 351M and 400M have 8 valve cover bolts. The easiest way to tell a 302 from a 351W is to measure across the intake bolts. The 302 is approximately 71/2 inches wide, the 351 W will measure out at 91/4 inches. The distributor turns counter-clockwise on all Ford V-8s, so that won't help you.
351w swap headers
351w intake (or just the lower for what you've got)
fuel rails - modify your stock ones or buy a kit like that Mallory one in the Summit catalog.
All the sensors will come over (except the low oil in-the-pan sensor)
The timing cover bolts tight up off the 302
The motorsport pan kit works well so long as you use a Std. oil pump (no High volume)
If you want oil pan rails (like you have on the 302), get 'em from a '95 Lightning at your Ford dealer
The front sway bar doesn't fit anymore - I think one off an SN-95 would solve the problem (brackets and all)
For a distributor, I used one from an '88 Truck 5.8L and swapped the distributor gear for the steel one off the 302 one.
The A/C and Power Steering bracket is cheap from FMS (for a fox car)
cut the smog tube on the back of the heads and lengthen it with a length of silicone hose
you'll have to lengthen the vacuum line that goes to the fuel pressure regulator by about 1"
You'll need to find a hood that'll clear your intake. I use the TFS intake and my 4" Cobra 'R' hood still hit by the throttle body. Some of the cowl / Cobra 'R' hoods are wider at the base of the windshield - this is your BEST FREIND.

351 Mustang Parts List
Parts to order from Ford Motorsport
Description Part Number
Lightning Shortblock (Roller Ready) M-6009-B58
Cobra Intake Kit, 351W (6) M-9424-D50 Upper, M-9461-A58 Lower
Cobra Intake Center Bolts Get these from PPI
Intake Manifold Bolt Kit (8) M-6002-A50
Oil Pan Kit, 351W M-6675-A58
Crank pulley spacer M-8510-B351
Crankshaft damper M-6316-C351 or E8TE-6316-A3A (E8 part is used on '95 Cobra R)
Shorty Headers ('79-'93 / '94-'95) M-9430-A58 / M-9430-R58
Header Gaskets M-9448-A302
Accessory Bracket (A/C / A/C delete)(9) M-8511-B351 / M-8511-A351
Hydraulic Roller Lifters(1) M-6500-R302
Flywheel 28.2oz imbalance (5sp only) M-6375-A302
HD Clutch Kit (5sp only) M-7560-A302
Shorty Headers (79-93) M-9430-A58

Parts to order from Ford
Description Part Number
Pushrod(1)s F4TZ-6565-C (94 F-150)
M-6565-A58 5.8L Hydraulic Roller Tappet
D8OE-6565-A1A 5.8L Flat Tappet
Timing Chain Cover ('93-down / '94-up) E3AE-6019-A / F1SE-6P041-AB
Timing Chain Cover Bolts (8) (2) 56126-S2 (3), 56131-S2(4), 56135-S2(1), 56123-S2(2), 388551-S2(1)(Stud)
Waterpump bolts(8) (2) ???
Coolant Transfer Tubes(4) F3ZE-9D424-AA
Distributor, 351W EFI ('93-down / '94-up)(2) D7TE-12127-D / E9TE-12127-CA
Hydraulic Lifter Guide Plates(1) E5ZZ-6K512-A
Lifter Guide Plate Retainer(1) F0AZ-6C515-A
(1)(5)Lifter Guide Plate Retainer Bolts ???
Coolant Bypass Hose E7SZ-18472-A
Coolant Hose (Pump to Transfer Tube) ???
Oil Pan Reinforcement, 5.8, Right Side E7AZ-6A74-C
Oil Pan Reinforcement, 5.8, Left Side E7AZ-6A74-D
Oil Pan Bolts 1/4" 390658-S2
Oil Pan Bolts 5/16" 390657-S2
Oil Pump Pickup Bolt (7) 357235-S
(7)Oil Pump Pickup to maincap bolt mounting locknut 382802-S191
Oil Pump Bolt/Lockwasher (size??) (5) 382951-S
(3)ECT Sensor F2AZ-12A648-A
(3)ACT Sensor F2DZ-12A697-A
(3)Block Plate D9ZZ-7007-A
(3)Bolt, Flywheel to Crankshaft 1ZZ-6379-A or 39127-S
Lower Gasket Set E9AZ-6E078-B
Intake Gasket Set F3TZ-9433-D
(8)(5)Throttle Body to Intake Mounting Bolts 45357-S8
Timing Pointer F1TE-6023-BA
Balancer Bolt E0AZ-6A340-A or 376706-S
Balancer Washer EDC-6378-A

351W Conversions, Every Nut and Bolt

This Water Box was supposed to be Part II of How To Make Your Mustang Hook, but with the introduction of the new 351W Sportsman shortblock we have been bombarded with the same question from dozens of people: "What do I need besides the shortblock?" The traction trilogy will continue shortly.

We have been doing 351W conversions for a fairly long time and are a big fan of the extra cubes and additional strength offered by a 351W over a 302 or 302 stroker. Be sure to check out several stories in the Water Box Archives to understand why we like them so much. But we have never sat down and listed all the miscellaneous parts you need for a complete conversion. Usually people think all you need is the oil pan kit, a lower intake and headers. While these are some of the major parts, there are dozens of lesser parts that are just as important.

We have tried to list every single necessary component we can think of. While some of you may have sticker shock after adding up all the individual parts, it's important to remember that many of these same costs are encountered when building a healthy 302 or 302 stroker. If you already have a lot of money invested in quality 302 parts, a 351W may not seem attractive. But for those that do not have to take a loss on expensive headers and a ported lower intake, a 351W conversion may make more sense than a 302 stroker considering the extremely affordable $1695 price of a Sportsman Shortblock and the fact that it is several times stronger than a stroked factory 302 block.

The parts list below makes the assumption that a pair of quality heads, roller rockers, roller lifters, adequate fuel injectors, at least a 65mm throttle body and upper intake are already owned. You'll also need to hold on to your stock water pump and timing cover. If your 302 is pretty much a virgin, you'll need to buy these major components, but you would have to have done the same for a 302 build up. No one ever said that horsepower was cheap. Smokey Yunick once asked a customer "How fast do you want to spend?"

In some cases, you may be able to substitute other parts than the ones we have listed that will raise or lower the total you come up with. Also note that some of the parts are not necessary depending on your combination. An 86 - 93 conversion uses almost all the same parts as a 94 - 95 conversion, so prices will be nearly identical. Also left out of the equation are motor mounts that lower the engine a bit, while not absolutely necessary, they help provide extra hood clearance. HPM "drop solid" mounts are a nice piece and drop the engine 3/4".

Part Price
SVO Sportsman Shortblock $1695
Oil Pump $35
Oil Pump Shaft $15
SVO Oil Pan Kit $145
GT-40 351W Lower Intake $309
SVO 351W Dampr $269
Stock Type 351W Dampr (Brand New) $189
ARP 1/2" Under Cut Head Studs $139
Mac Shorty Headers $189
Mac Long Tube Headers $289
Correct Length Push Rods for Hydraulic Roller $85
Flexplate for AOD or C-4 $80
10.5" Steel SFI Flywheel - 28 oz balance $249
Air Conditioning and Power Steering Bracket $60
Power Steering Only Bracket $50
Truck EFI Distributor $189
Steel Distributor Gear $35
Modify Vortech/Paxton/Powerdyne Bracket $175
H.O. Fibertrends Hood with at Least a 1 1/2" Rise $385 + paint
Complete Fel-Pro Race Gasket Set $159
Motorsport or other Hydraulic Roller Cam $229
SVO Timing Chain Set $69
Magnecor Spark Plug Wires $69
Oil, Coolant $20 - $45
Labor to assemble 351W, R&R engine, tune $800 - $1200

We've tried to be absolutely as thorough as possible in listing all these parts. But depending on particular combinations you may still need one or two things. It's impossible for us to foresee everything with so many possible combinations.

So now you know what you're in for if you decide to take the plunge and install an engine that has a better rod ratio than any 302 stroker and offers the strength of an A4 block.

Now let's focus on 351W conversions. We've built and installed dozens of 351W's in late model Mustangs and the results are very positive. The 351W is the answer to many of the 302's weaknesses. Even a late model 351W block ('79 - present), which is the weakest of all 351W castings, is significantly stronger than any production 302 including pre '81 302 blocks. The blocks are so much more rigid than 302's that while trying to squeeze every last hp out of our 351W '88 LX at Maple Grove, we detonated the engine hard enough to brake 2 pistons. Breaking pistons may sound like a tragedy, but it showed how well the 351W keeps head gaskets in place, all we were using were Fel-Pro 1011-1's, they weren't high tech head gaskets. If it had been a late model 302 block, we would have easily blown 4 sets of head gaskets during the weeks leading up to Maple Grove.

The 351W also offers a more desirable rod ratio compared to a stroked 302. And let's not forget that a 351W can be stroked (but that's a different Water Box altogether). But perhaps the greatest benefit over a stroked 302 is the cost. A 351W shortblock directly from SVO is only around $1300. If you're looking to build a 351W from scratch, you should have no problem finding a good core at a salvage yard, and the final cost - using good steel rods and quality forged pistons will still be roughly the same as stroking a late model 302, but the 351W will be much stronger and more reliable.

Now you're asking, what are the drawbacks to a 351W conversion. Well, you'll need a cowl or other raised hood with a 1 1/2" rise, a new lower intake manifold, new headers, one modified front dress bracket, and a new oil pan which can be purchased from SVO with a pick-up for only $135.00. A 351W can also give away the element of surprise to suspicious onlookers, but the vast majority of people fail to notice the difference in deck height, especially with an EFI engine that has a lot of accessories, plumbing and wiring.

So, for the average enthusiast who wants more cubic inches without going broke, a 351W conversion is a better choice than stroking the inherently weak factory 302 block. Both will make approximately the same power, and cost roughly the same, but the 351W will be more reliable and much stronger, unless of course you opted for the A4 block. But don't misunderstand the purpose of this article. We are in no way saying that stroked 302's are unattractive, we've built several and all have worked out well. But when stroking a 302, we have always used Motorsport A4 blocks, so they're not a budget oriented project that the average enthusiast can undertake
  • Like
Reactions: 1 user


15 Year Member
Mar 31, 2005
Revised - 7/12/11
Current & Updated info is now posted here...
351w Fox Body Swap

Not Found - Webs.com
I'm not sure when the freewebs site was last updated, and I don't maintain it anymore.

302 to 351W Swap in a Fox Body Mustang

This FAQ was written for converting a T-5 5.0 efi Mustang to a T-5 351w efi Mustang. The conversion will be slightly different if starting with a 2.3l or carbureted Mustang OR converting to a carbureted 351w. Converting transmissions is beyond the scope of this document.

Background Info-
The major disadvantage of the 302 is its lack of strength at high power levels. Most will agree that at ~500hp the factory 302 block will try to split in half. For many the solution to this is an aftermarket 302 block, which can be expensive.

Another alternative is to swap in a 351w block. The 351w is supported by the aftermarket nearly as well as the 302, but can handle much more power than the 302. Some common safe power numbers given for the 351w are usually in the 600-700hp range. There are 2 basic production blocks available; the 69-70 blocks had a deck height of 9.480”, and the 71 up blocks had a deck height of 9.503.” This is compared to the 302 deck height of 8.200”.

351w Casting Numbers -
The casting numbers are on the passenger side near the starter location. You will have to turn the block upside down, or use a mirror to see them.

The year will be designated by the first 2 digits of the casting number.

The first digit is the decade and will be a letter. C=1960's, D=1970's, E=1980's, and so on. The second digit will be a number and specifies the year of the decade. Some examples follow:

For more info on how to identify various Ford engine blocks check out the following link…


Getting Into the Nitty-Gritty

The 351w Engine Block -
69-70 - High Nickel content and thicker main webs (These are the only Production Ford 9.480" Deck Height 351w blocks)
71-74 - Reduced Nickel content thinner main webs (71-up had 9.503" Deck Height)
75-91 - Reduced main web thickness
92-On - Lifter Bores were lengthened to accept roller lifters

There were some 351w Mexican blocks as well. The early versions of which are desirable due to their beefier castings and higher nickel contents. A Mexican block can be identified by the useless looking knobs cast into the block on either side of the timing cover, and an “Hencho en Mexico” cast into the lifter valley. Mexican blocks were supposedly used on some US vehicles, but they are a fairly rare find.

Camshaft and Lifters-
The specs of the cam will depend mostly on what your goals are for the motor. Cam spec selection is way beyond the scope of this FAQ. What you want to watch out for is selecting the correct base circle for the lifter combination and using the stock 302 HO firing order (since you are most likely reusing the stock 302 computer).

NOTE: The firing order of the cam must match the firing order of the ecu. Carb motors are not restricted this way.

69-91 351w blocks -
Roller Lifter Option 1) Standard Base Circle Cam / Aftermarket Linked Bar Hydraulic Roller Lifters
Roller Lifter Option 2) Small Base Circle Cam / 302 HO Roller Lifters

92 & Later 351w blocks -
The Standard Base Circle Cam can be used with 302 HO Roller Lifters.
A Small Base Circle Cam is not needed in these blocks.
(The 92 and later "roller" blocks will have a F4TE casted into the block near the starter)

If using solid lifters (either flat tappet or roller) then a standard base circle cam can be used on any year 351w block.

If in doubt, ask the company you plan on purchasing the cam from (or better yet a reputable engine builder) what would be appropriate for your application. They will need to know what year the block is and what lifters you plan on running. Additionally it may be helpful to have your rocker ratio available, and what piston you will be using if not stock.

NOTE: Small Base Circle Cams are known to be less than ideal, as they are weaker. There are not as many cam profiles available for the Small Base Circle Cams, so your Off the Shelf Cam selection will be severely limited. If possible, it is recommended to avoid the Small Base Circle Cams.

Firing Orders-
Early 289 & 302 1-5-4-2-6-3-7-8
302HO & 351w 1-3-7-2-6-5-4-8 (this is all 83-93 Mustangs, and all 5.0 Explorers)

NOTE: The firing order of the cam must match the firing order of the ecu. Carb motors are not restricted this way.

Again, there are far too many options available to cover here. Check with the cam manufacturer on what length pushrod you will need. Or even better, you can use a pushrod length checker and measure them yourself.

Roller Lifters-
The stock 302 lifters can be swapped over to the 351w (see the cam discussion above) with a little machining/grinding and a reduced base circle cam.

First the spider will require 2 holes to be drilled in the main valley. These holes will be drilled over the cam bearings, so great care should be taken not to damage the camshaft or bearings. Risk can be minimized by removing the camshaft, and drilling the holes before the cam bearings are installed. Some grinding may need to be done to allow the factory 302 dogbones to sit flush on the 351w block as well. A Dremel is adequate to get the job done. Be patient and work slow; it is easier to remove material than put it back. Of course it would be best to do this work before having the block cleaned and prepped for assembly. Ford Hydraulic Roller lifter (for both the 302 and 351w) part number is M-6500-302.

If all of this does not sound appealing to you then maybe some of the aftermarket roller lifters will be a better option. These tend to be fairly expensive however. Look for lifter pairs that have a link bar, connecting each pair of lifters.

Rocker Arms-
This will depend on the heads you select. All of the same rules that apply to selecting rockers for a 302 still apply to the 351w. Options to consider are Pedestal vs. Stud Mount, Roller vs. Non-Roller, and Brand.

Engine Mounts-
Stock 5.0 mounts will bolt up to the 351w. Aftermarket alternatives include solid mounts and polyurethane mounts. Convertible Engine mounts are rumored to be stronger & shorter. Another alternative is a set of lowering engine mounts from either Year One, Moroso, or HP Motorsports (HPM). These are solid and lower the motor ~¾”. Lowering engine mounts are useful for gaining hood clearance, but will also reduce clearance between the oil pan and stock k-member. This presents clearance issues with some aftermarket pans and stock k-members, but should be ok for the FRPP pan. The use of an aftermarket tubular k-member may help improve clearance with aftermarket oil pans.

Un-Confirmed –
From 87-90 the convertible Mustang had the “captured” mount design, while the Hardtops had the standard design. The captured style mounts are said to be ½” to 1” lower, and to be stronger.
In 90 and later Mustangs, ALL were equipped with the captured design.
Aftermarket Prothane mounts are said to mimic the design of the early Hardtops. While the Energy mounts are said to mimic the convertible “captured” mounts. So, Energy Engine Mounts should be the same height as the 87-90 convertible “captured” motor mounts

302 heads are basically the same as the 351w heads with the exception of the head bolt diameter. 302 heads have a 7/16” head bolt hole and the 351w has a ½” head bolt. Opening the holes can be done by hand, if done with care. It would be best to send this work to a machine shop however. Keep in mind however, that even ported E7 heads are considered to be restrictive on a modified 302. Putting E7 heads on a 351w will limit the potential of the motor. Look to the Aftermarket companies like AFR, TrickFlow, Edelbrock, Holley, and Canfield. Most of these heads will make more power out of the box, than an E7 with full port work.

Exhaust Headers-
Stock 302 headers will bolt up to the head of a 351w (since the heads are basically the same), but will not mate up to the factory 302 mid-pipe due to the extra width of the 351w, and may even make contact with the transmission tunnel. There are many aftermarket suppliers of 351w Fox Body Swap headers including MAC, FRPP, Kooks, Hooker, and Hedman. The Ford shorty headers are p/n M-9430-A58.

Intake Manifold-
Since the lifter valley of the taller 351w is wider than the 302, a new lower intake is required. Aftermarket suppliers of 351w intakes are numerous. Most of these companies offer a 351w lower intake that will bolt up to their 302 upper intakes, which many Mustang owners may already have. Being able to reuse your current upper intake can present a significant $ savings.

NOTE: It is often rumored that the stock Mustang upper will bolt up to a stock 351w EFI truck lower. No such combination has actually been found to work though.

However –
As of December of '06 there is a new product available for adapting a truck 351w EFI lower intake, to a Fox Mustang Upper intake. The adapter can be found through B.C. Broncos at B.C. Broncos. Here is a link directly to the adapter products new home -

Be cautious with intake height if you are trying to clear a stock hood. If the above mentioned drop motor mounts are not used then, another option for gaining hood clearance, is to cut down the upper intake. This is easier on the plastic box upper from Comp Cams, as the aluminum intakes will require cutting/welding followed by machining to square up the mating surface.

Shortening the upper intake will cause clearance issues between the TB and valve cover if the upper is trimmed more than ~¾”. Keep in mind that TrickFlow and many other aftermarket head companies have raised the valve cover flange up to .300” which will limit how much you can trim from the upper intake. Of course the use of tall aftermarket valve covers will be somewhat restricted as well. If you do plan on cutting the upper intake, be sure to do a full mock up with all parts that will be installed later. The part numbers for the Ford 351w Cobra/Lightning manifold are as follows; Upper M-9424-D50 / Lower M-9461-D58.

Oil Pan-
The 351w oil pan rails are wider so a new oil pan is required. The lowest cost option is probably the FRPP 351w pan for Fox Body applications (M-6675-A58). Aftermarket companies have standard volume, high volume, drag race, and road race pans available. A pan specific pickup tube and dipstick will also be necessary. If using a main girdle and/or windage tray, be sure to select an oil pan that will clear these added components. If you can find them, the 351w equipped Crown Victoria and Grand Marquis had an oil pan that will fit in your Fox Body Mustang.

Oil Pump-
The 351w oil pump is different from the 302 (mostly external). These are readily available in standard volume, high volume, and high pressure models.

Oil Pump Driveshaft-
It is advisable to utilize a heavy duty oil pump driveshaft. The cost is minimal considering the importance.

If you find that the heavy duty oil pump driveshaft does not allow the distributor to fully seat (as may be the case with aftermarket shafts), then the best solution is to trim about .250” off the bottom of the distributor. This happens because Ford changed the dimensions of the distributor, but most aftermarket companies (like ARP) didn’t change the dimensions of the oil pump driveshaft to match. Having to trim the distributor should not prevent you from using a heavy duty pump shaft.

The distributor in the 351w is the same length as the 302 distributor. However, the 351w does use a larger diameter Oil Pump Drive Shaft. The larger drive shaft will require the larger diameter distributor shaft. The shaft diameter of the 302 distributor is ~.40”, while the 351w distributor is ~.53”. The 351w oil pump shaft input size is ~.31” and the 302 oil pump shaft input size is ~.22”.

A 351w distributor can be sourced from several stock Ford factory EFI applications; mostly pickup trucks/vans, but any EFI 351w will work. Some aftermarket suppliers do have electronic/TFI distributors available, such as MSD and Accel.

Be sure that the cam drive gear is appropriate for your application. Roller cams require a steel dist. gear.

As mentioned in the ‘Oil Pump Driveshaft’ section there is a potential for interference between the distributor and pump driveshaft. The best solution is to trim about .250” from the distributor.

Engine Management-
Any stock 302 computer will handle a mild to moderate 351w swap. The EEC-IV will be fine with larger injectors, heads, intake, and cam. Aftermarket plug in style chips are not going to offer ideal performance. The best solution is to invest in a chassis dyno tune or an EEC-IV computer tuning system, such as a TwEECer.

Flywheel/Flexplate & Starter
The counter weight of the 5.0 is 50oz. The 351w counterweight is 28oz. You can reuse your 5.0 flywheel if you have it rebalanced at a machine shop. This is probably the easiest and most cost effective alternative. If purchasing new parts just make sure that the flywheel weight and starter tooth count are correct for the other components you already have. Ford flywheel M-6375-A302.

Harmonic Damper-
Again this must be matched to the 28oz. counterweight of the 351w. Another consideration here is getting the crank pulley to line up with the rest of the serpentine belt system. Many aftermarket dampers will come with an appropriate spacer for this application. FRPP does have a damper available specifically for this application (Damper M-6316-C351, and spacer M-8510-A351 or -B351 or -C351)

Thanks to r.barn, who has contributed the following links regarding the Ford spacers…
Ford Racing Performance Parts

Fuel Injector Rails-
The stock 302 rails will not be wide enough to fit the wider 351w lower intake. However, if the flex line in the front and rear of the stock rails is removed and replaced with longer sections of high pressure fuel line the stock rails will work just fine. Simply cut out the stock flex line and replace it with high pressure fuel line, available from any parts store. A couple of hose clamps will secure the hose in place. It is also important to make sure the hose does not rub on anything.

Fuel Injectors-
Proper injector size will depend on the application. A mostly stock 351w will be ok with 19lb injectors, but with the addition of an intake & Throttle Body (with stock heads/cam) will most likely require 24lb injectors.

Fuel Pump-
A 190lph pump is recommended for mildly modified Mustangs. If an all stock 351w is being swapped in, then the stock fuel pump may be adequate. It should be noted that due to the re-circulating nature of the Mustang fuel system, installing a pump that is too large is not an issue. If in doubt, go with a larger fuel pump.

Heater Core Hoses-
The stock 302 routed the heater core coolant through metal tubes on the passenger side of the lower intake manifold. These metal tubes may or may not bolt up to the 351w lower intake. Either the tubes can be replaced with tubes from another application (junkyard parts), or heater hose can be used to replace the metal tubing. Just be careful that the hose will not bind or rub anywhere, especially the throttle linkage.

This is the only stock 5.0 accessory bracket that requires modification. The original AC pump and Power Steering pump can be reused if an FRPP bracket is used. If using Power Steering only (without A/C), the FRPP part number is M-8511-A351. For both AC and PS applications the FRPP number is M-8511-B351.

Most emissions equipment can be swapped over, and will be required if the car is to pass emissions testing. The smog pump will present few challenges, as the 302 pump bracket will bolt directly to the 351w. Mostly of the difficulty with the air pump will come when ensuring clearance between the headers and pump hoses.

The EGR setup will vary depending on the application. The stock 302 routed the EGR gasses through the lower/upper intake. With some creativity the AIR passages on smog legal heads can be used for EGR, in fact several factory applications used a similar crossover pipe, which routed the exhaust gasses from the heads up to the EGR valve. These crossover pipes can be found on 351w equipped trucks and vans.

Some State Inspections Agencies (California) will require the use of the Emissions equipment that was used on the factory application the motor was sourced from. If you pull your 351w from an F150, you may be required to install the smog pump, EGR, etc. from the F150.

The easy way to do it is get a taller cowl hood to replace the stock hood. This offers the aggressive look that many are looking for. If desired though, the 351w can clear the stock hood. Clearance will depend on engine mounts and intake manifold selection/modification. If necessary some of the bracing on the underside of the hood can be cut away, and the insulation mat can be removed. In general at least 3/4" will probably need to be trimmed off the height of the new 351w motor, but this will vary greatly with each combination. The reduced height can be achieved with lowering engine mounts (as mentioned under the engine mount section), or by shortening the intake manifold (as mentioned in the intake manifold section). There will be some mock-up needed for each application.

Spark Plug Wires
Some Vacuum hoses may need to be lengthened or shortened
Accessory drive belt length will most likely change (Measure for best results)

Items Not Affected By the Conversion-
Transmission - Be sure to use the correct input shaft bearing in the crank
Valve Covers
Belt Tensioner
Water Pump
Timing Cover
Radiator and hoses
Timing Chain
Oil Filter (the 351w uses the same part number)
Head Gaskets (same part numbers apply)

Desirable Upgrades-
3 core Radiator and Electric fan
Subframe Connectors
Tubular K-member (if clearance issues are feared)
Z-spec T-5 (or other high power upgrade)
Torque box Reinforcements
2.5” or larger exhaust
1 5/8 headers should be considered a minimum with 1 ¾ being ideal.


15 Year Member
Mar 31, 2005
It says the sway bar won't work with the 351. Is this true?

I still have mine...

The clearance between the bar and the oil pan gets a little tight, but most oil pans should clear just fine... if using standard motor mounts.

I don't know what would happen if solid 3/4" drop mounts were used? :shrug:

I have made revisions to my writeup (above), so I edited the above post.
Current version will always be on my site...



New Member
Jun 4, 2007
All of the swap info I read hints that somewhere, someone has used drop mounts and an intake setup that clears the stock hood. Does anyone have any pictures, links or info on this, most specifically if any of the standard aftermarket EFI intakes with solid mounts can be made to fit under there?


15 Year Member
Mar 31, 2005
All of the swap info I read hints that somewhere, someone has used drop mounts and an intake setup that clears the stock hood. Does anyone have any pictures, links or info on this, most specifically if any of the standard aftermarket EFI intakes with solid mounts can be made to fit under there?

I cleared my stock hood
Lightning lower intake
Comp Cams Box upper intake
Energy Suspension motor mounts
Stock K-member

I had to machine the bottom of the Box intake to make it about .700" shorter.
I could have trimmed more off the intake, but I then I wouldn't have any clearance between the TB linkage and the valve cover.

Let me know if you have more specific questions...