351w or 5.8 fox swap info?

my289eatsrice · Nov 11, 2005

Does anyone have the info needed for my 351w swap? I have a mostly stock 1991 mustang gt that has a tired 5.0 ---I have a 1996 351W full roller rebuilt block with stock heads and need to know all of the necessary items needed for the swap. Also, i would like to know some combinations for making some good power, preferably 330 to 350 wheel horsepower. I am on a budget so i would like to know some good combinations while keeping my car EFI.

srothfuss · Nov 11, 2005

You'll have to search thru all of the threads to find the information that you seek. There used to be a great write up that was sticky but the thread was deleted.... crapola

vristang · Nov 11, 2005

This is a draft, so please post if something could be added, or is just wrong

jrichker has a copy of most of the 351w swap sticky. Try to pm him.

If you have specific questions do not hesitate to post them. I feel the swap is very worth while, so I try to respond to all of these questions.

Here is a discussion I put together a while back.

351W Swap In A Fox Body Mustang
VRISTANG

Note: This discussion focuses on EFI conversions as this is the most common route taken.

Engine Mounts-
Stock 5.0 mounts will bolt up to the 351w. Aftermarket alternatives include solid mounts and polyurethane mounts. Convertible Engine mounts are supposedly reinforced / stronger. Another alternative is lowering engine mounts from HP Motorsports. These are solid and lower the motor ¾”. Lowering engine mounts will reduce clearance between the oil pan and k-member. This presents clearance issues with some aftermarket pans and stock k-members, but should be ok for the FRPP pan.

Heads-
302 heads are 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 or sent out to a machine shop.

Exhaust Headers-
Stock 302 headers will bolt up the head of a 351w (since the heads are basically the same), but will not mate up to the mid-pipe due to the extra width of the 351w. There are many aftermarket suppliers of 351w Fox Body headers including MAC, FRPP, Kooks, Hooker, and Hedman.

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. Some 351w lowers will bolt up to standard 302 upper intakes, which can help reduce conversion costs. Be cautious with intake height if you are trying to clear a stock hood. Another option is to cut down the upper intake (This is easier on the plastic box upper from Comp Cams. This will cause clearance issues between the TB and valve cover if the upper is trimmed more than ¾”).

Oil Pan-
The 351w is wider so a new oil pan is required. The lowest cost option is probably the FRPP 351w pan for Fox Body applications. 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.

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.

Distributor-
The taller 351w does require a longer distributor. This can found from several stock Ford factory applications, mostly pickup trucks/vans. 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.

Engine Management-
Any stock 302 computer will handle a 351w. The EEC-IV will be fine until the combination gets more dramatic 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.

Flywheel/Flexplate & Starter
The counter weight of the 5.0 is 50oz. The 351w counterweight is 28oz. You can reuse a 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.

Harmonic Damper-
Again this must be matched to the counterweight of the 351w. Another consideration here is getting the crank pulley to line up with the rest of the serpentine belt system. FRPP does have a damper available specifically for this application.

Fuel Injector Rails-
The stock 302 rails will not be wide enough to fit the wider 351w lower intake. 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.

Fuel Injectors-
Proper injector size will depend on the application.

AC/PS-
This is the only stock 5.0 accessory bracket that requires modification. The stock AC pump and Power Steering pump will bolt up if a ford bracket is used. Without AC (PS only) the FRPP part number is M-8511-A351. For both AC and PS applications the FRPP number is M-8511-B351.

Emissions-
The crossover tube from a 302 can be used if it is cut and a section of high temp hose is used. The 302 air pump will bolt up correctly, and there should be no issues with the air injection system. The EGR should mount up properly, but this will vary with intake manifold selection. Routing of EGR hoses may need to be modified.

Hood-
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. If necessary some of the bracing on the underside of the hood can be cut away.

Items Not Affected By The Conversion

Transmission- Just be sure to use the correct input shaft bearing in the crank.
Bellhousing-
Valve Covers
Water Pump
Altenator
Clutch
Timing Cover
Radiator
Timing Chain

macx · Nov 11, 2005

Here's my write-up on a 351 into an 89 Linc Mk7,
which is just a stretched Fox chassis.

I was on a really tight budget, so you'll see what
I came up with for combo. The one thing you
could maybe do for more higher rpm power would
be to go to a different cam, but I wouldn't
recommend one of the alphabet cams. I'd
look for a Comp, Crower, or maybe Crane.
I purposely went for low and mid range torque,
and I've got a heavy car and had to keep
"highway" gears, and yes I could have done better,
but I got the cam I've got for $40. And I do get good
mileage and still have good torque and throttle
response in street driving rpm ranges. See the article.

www.lincolnsonline.com/article144.html

macxx1@excite.com if I can be of any help

my289eatsrice · Nov 13, 2005

Thanks for all your info, If anyone finds anything else on the topic, then just add on. I would also like to know if it's worth keeping the stock piston, and porting out the stock heads, or if I should dish out $1200 for some trick flow or AFR's for the 330 to 350 relyable hp to the wheels that I am looking for. Thanks.

vristang · Nov 13, 2005

my289eatsrice said:
Thanks for all your info, If anyone finds anything else on the topic, then just add on. I would also like to know if it's worth keeping the stock piston, and porting out the stock heads, or if I should dish out $1200 for some trick flow or AFR's for the 330 to 350 relyable hp to the wheels that I am looking for. Thanks.

I am a big fan of the TF TW heads. The AFRs will produce better flow numbers, but the tw heads have a different design to the combustion chamber. The design difference allows for better combustion efficiency.

For some flow numbers check out this site...
http://web.archive.org/web/20001018091118/www.fordmuscle.com/archives/2000/05/heads/index2.shtml
There are many other sites like this, and Google should be able to locate them.

Keep in mind though that flow numbers are only one part of selecting an appropriate head for your application.
Other factors like swirl/tumble play a major role in the quality of the combustion process, but cannot be quantified in a flow test. It is these factors that help the trick flows to perform so well in specific applications.

High lift with TF heads will require either machined pistons or new pistons.

my289eatsrice · Nov 14, 2005

So, which would be work the best with my application. The motor has the F-303 cam, which is 550's lift or something close, and what do you think of the trick flow track heat heads? because i have heard some good stuff from guys who have used those. I just want to keep a reliable 350 hp to the wheels for the start of the build, so i figure either the AFR 185's or track heat heads, lemme know

FORCED2DV8 · Nov 14, 2005

I would go with the AFR 185's And get a matching camshaft, depends on your needs, with the good heads and a decent cam you should have 350 hp no problem.

Zero_chance · Nov 14, 2005

Hey tom, know what will help you out? If you sell me your turbine wheels. Youll definitely get 350 horsepower from that....

my289eatsrice · Nov 15, 2005

My motor already has a brand new F-303 cam, so would the trick flow heads and AFR's both work well, or which ones would be more suited for the cam?

351w or 5.8 fox swap info?

my289eatsrice

New Member

srothfuss

Last night I stabbed the same guy 7 times in a row

vristang

macx

New Member

my289eatsrice

New Member

vristang

my289eatsrice

New Member

FORCED2DV8

New Member

Zero_chance

my289eatsrice

New Member

Similar threads

351w or 5.8 fox swap info?

New Member

Last night I stabbed the same guy 7 times in a row

New Member

New Member

New Member

New Member

New Member

Similar threads

Privacy & Transparency

Privacy & Transparency