351m in a 79

Any fox style motor mount will work. BUT... you're screwed for headers. Hooker makes a set for 351C's, but the M is over an inch wider... plus it's a boat anchor. Toss it and go find a C if you want a Cleveland based motor.

The 351M engine has a very small aftermarket. Typically many go ahead and stroke it to the 400" (4.00" stroke), reuse the rods, and get some shorter pistons. The stock 351M compression is in the low 8:1

There is only a couple choices for intakes, Wiend, Edelbrock 400 SP-2, etc.

10.3" deck is okay, but not good for the aftermarket offerings, but they aren't very strong 351 blocks anyways.

Good Luck.

Why are we doing this?

make sure u have th same oil pickup for the morso oil pan...get polly urathane engine mouths n tranny mounts...might neeed sway bar bushing spacers for the front....and a cowl hoood depending on the setup u go with....

79 mustang ?

was the car a v 8 car new or a 4 or 6 banger car my friend had a 79 4or 6 banger car and was putting a 302 in it and the k member was the wrong onehehdto install the 302 k member

Does summit even make a pan to put a 351m in a fox, i bet you have a Oil pan for a Windsor motor.

95GTAODE said:

Any fox style motor mount will work. BUT... you're screwed for headers. Hooker makes a set for 351C's, but the M is over an inch wider... plus it's a boat anchor. Toss it and go find a C if you want a Cleveland based motor.

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lol, why?? they're close enough, that he can use what he has.

as mentioned, swap the crank and pistons to take it to 400, however that engine is a HORRIBLE match for the fox. It's heavy, way way way too heavy!! not only that, in stock trim, it's only making 158-170 horse, and not much more torque than that.

It can be built into quite the screamer though, but you're gonna pay.

why doesn't he just grab a $300 used 87+ 5.0 roller motor or 5.8 bronco/f150 motor and run with that?? so much less hassle!

well, I'm doing the same thing using a 434, cuz I like to be different.. So far two things: 3 bolt mounts. 79 Tbird mounts are close, but no cigar. I plan on going back to the truck mounts, and machining a lower piece to fit...kinda like a triangle. This is in an '87 Turbo Coupe, which has a different mount set-up than Mustang. However, I'm looking to put a Mustang K-member in for header clearance, and so that may change.

Secondly, the oil pan has to be a rear sump pan. A cleveland pan will fit, but needs some modifying. It'll require cutting and welding a slight half-circle indentation into the forward half. http://www.geocities.com/idfergusson/351c_swap.html?200710

Reviving an old thread, perhaps, but I'm curious to if any progress has been made.

Remember, the 400 is a Cleveland but with a longer stroke, and 2v Cleveland heads, starting in 1971. 1972 was when they started smogging them. 1975, the 351M came about as a de-stroked 400. Only difference is crank and pistons. An aluminum intake alone will shave off about 60 lbs. A bigger problem is the need for a different transmission/bellhousing for the BB pattern.

Comprimise HP just to be different?...Not to Smart.

A 351 Modified will cost at least twice as much to build, ending up with an engine that has a narrower power band, lower overall horsepower, and a much higher amount of weight compared to its 302 or Windsor counterparts. And this is all just in relation to the engine itself, not to mention how much work is involved in PROPERLY mounting such a useless beast of an engine in what should be a nimble street or strip performance vehicle like the fox-body.

Is the 351M all bad? NO. This engine can be used efficiently in some towing situations due to its ability to provide decent amounts of torque in a safe way. (When I say “safe”, I am referring to its low stock compression ratio which allows the engine to run at a usable torque level for a long period of time on pump gas.) This power plant can also perform in high or low levels of temperature for extended periods, making it a good economical, truck engine……exactly what ford designed it for.

So to compromise your car and your wallet just to be different would not be recommended to anyone reading this.(For some reason I think the person this reply is actually intended for may have their mind already set on this ridiculous decision though.) If you are someone looking for a good engine to swap into your fox-body, choose a 351w due to its low weight, high horsepower potential, avalibility of aftermarket parts, and parts specifically intended for swap into a fox-body. You will save money and blow the doors off of anyone with a 351 Modified in their sad car, but then again a STOCK 302 will most likely achieve this same feat.

Even if someone has a 351M that they invested the multiples of thousands of dollars it would take to get some horsepower out of it, you can sleep peacefully knowing that just a few bolt-on engine upgrades will allow you to most likely run much faster than any 351M out there.

As far as just doing this to be “different”, you’ll be different alright. You will be one of the only “Swapped-Engine” Fox-Bodies that will be getting passed by stock Camaros……not exactly the type of “different” that I would like to have under my belt, but that is just my opinion. Seriously folks, if you’re considering putting a 351M in a car that just doesn’t want one…don’t , I mean a stock 5.0 will almost certainly out perform this engine in almost every way.

stroked351w said:

making it a good economical, truck engine……exactly what ford designed it for.

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Wrong.

The 351M and 400 were developed to meet tighter emissions standards and still provide ample torque for ford's larger cars. The M didn't replace the FE blocks in the F-series trucks until the mid 70s.


I think it's a cool swap. Everybody bad talks the 351s and 400s because they were anemic from the factory.

That's just like saying a 302 is junk because in 1976 it only made 136hp with the optional 4bbl carb.

Bottom line is it is a torquey big block, which shares many parts with the cleveland motor which give it the benefit of head which are very useable.

Even the 2V heads on the 351M and 400 are basically cleveland heads. Sporting huge valves and decent ports which can be worked.

Nobody builds them because there are cheaper ways to get power. The windsor engine family will always be the cheapest to build when it comes to ford v-8s.

If you take a 400 (or throw a 400 crank in a 351), get some flat top pistons cleveland pistons, (wirst pins will need bushings) and mill the heads down to get the compression up to ~9.5:1. Throw a healthy cam in place of the weak retarded from the factory stocker. Get a decent valve job and maybe open up the ports a bit, blends the bowls a little. Get an Eddy 4bbl intake and you're cooking. Very easy to make 350+hp and gobs of torque (did i mention the stroke on the 400 is longer than the 460!).

Keep and eye on the oiling as these blocks don't have the ideal supply of oil to one of the mains (#1 or 5 i can't recall). THere are some tricks the racers do to aid this (external oil lines etc).

The 400 in a mustang. She'll be heavy up front, but have stump pulling torque right from an idle.

One way is they block the #1 main bearing feed hole. The #1 main receives oil pressure from 2 holes. Blocking one hole conserves the pressure to feed the others. Then open the hole that would feed the cam bearing to the same size as #2-5 main bearing feed hole. This size should be 5/16" and go about 1" deep to just intersect the main feed line. (excerpted from Tim Meyer inc)

Also add an aftermarket timing chain set with the timing set "straight up" like it was in 1971. 1972 and later they factory retarded it 4 degrees. The block surface dimensions are very similar between 351M/400's and Windsors. Only the deck height is larger. This technically would make it a small block( a Chev term) and not a big block. Which makes sense, since the 302 will drop right into the same perches a 400 uses in a Ford truck. The main glitch in the Fox, is fitting the exhaust and making motor mounts. There just isn't enough room. With the 400's 4" stroke, with CHI heads, and a few other parts, I've seen them hold a flat torque rate at or above 500 ftlbs. This year's EMC, had Jon Kaase using the 400 and there was a couple other 400's entered, too. With availability of 460's dwindling, the 400 is only going to become more popular, IMO. Atleast here in mud truck country, they've all been bought up. Just my .02

Mike85000 said:

Wrong.

The 351M and 400 were developed to meet tighter emissions standards and still provide ample torque for ford's larger cars. The M didn't replace the FE blocks in the F-series trucks until the mid 70s.


I think it's a cool swap. Everybody bad talks the 351s and 400s because they were anemic from the factory.

That's just like saying a 302 is junk because in 1976 it only made 136hp with the optional 4bbl carb.

Bottom line is it is a torquey big block, which shares many parts with the cleveland motor which give it the benefit of head which are very useable.

Even the 2V heads on the 351M and 400 are basically cleveland heads. Sporting huge valves and decent ports which can be worked.

Nobody builds them because there are cheaper ways to get power. The windsor engine family will always be the cheapest to build when it comes to ford v-8s.

If you take a 400 (or throw a 400 crank in a 351), get some flat top pistons cleveland pistons, (wirst pins will need bushings) and mill the heads down to get the compression up to ~9.5:1. Throw a healthy cam in place of the weak retarded from the factory stocker. Get a decent valve job and maybe open up the ports a bit, blends the bowls a little. Get an Eddy 4bbl intake and you're cooking. Very easy to make 350+hp and gobs of torque (did i mention the stroke on the 400 is longer than the 460!).

Keep and eye on the oiling as these blocks don't have the ideal supply of oil to one of the mains (#1 or 5 i can't recall). THere are some tricks the racers do to aid this (external oil lines etc).

The 400 in a mustang. She'll be heavy up front, but have stump pulling torque right from an idle.

Click to expand...

just a quick note on this post, the m family isnt considered a big block, they use big block parts but are a seperate family I belive F85 or something 85

351C, 351M, 400 is the 335 series.
429, 460 is the 385 series
221, 260, 289, 302, 351W is the Windsor series
small block, big block is a Che^Y term.