whats the difference? i i kno that the 351c is used mostly in muscle cars, etc but whats the diff between the m and c. i was on the holley web site lookin for parts for my 351m and i couldnt really find much. it was all 351w stuff. even if it wasnt related to the valves or lifters or anything like that, for example, theintake manifolds and such. any info is apreciated.
-alex-

 

I'll try to answer as best that I can, but there may be some exceptions to what I say.

The 351M, 351W, and 351C all have the same bore and stroke. The 351W is a Windsor engine and shares block and head design and many parts with the other Windsor motors, such as the 302.

The 351M is a destroked 400 and is very different from the Windsor engines. The major difference is it has a dry intake manifold and the thermostat and housing are on the block.

The 351C is similar to the 351M in block and head design. It also has a dry intake manifold. However the 351C has a shorter deck height and a different bell housing bolt pattern.

Many 351C parts are interchangeable with 351M/400 engines. Aftermarket manufacturers like Holley and Edelbrock have all but ignored the 351M/400 engines. There are many performance parts available for the 351C, but the 351W enjoys the most aftermarket support from both Ford Motor Sport and others.

As I said before there are exceptions to this. With some work heads and cranks can be interchanged between Windsors and 351C/351M/400 motors. 351C-4V heads can be used on 351M/400 motors, also with some work.

Before you start any modification on any of these motors, consider what you want as an end product. If you must have port fuel injection, start with a 351W engine. If you want a stump puller start with a 351M/400 (or 460). If you want a screaming 12 second 8000 RPM muscle car start with a 351C.

 

Well put Danlee.

People who say it can't be done should not interrupt the person doing it.

 

There are some odd-ball 351M and 400 engines ('73 or '74 casting numbers I believe) that used the small block bellhousing pattern. This patterm is not as strong so you really don't want it but if you didn't know it was out there you might get one by accident.

Bob
'66 7 Litre, top loader, 3.25 Traction-lock, Sidewinder Intake, SCJ Exhaust
'88 F150 LWB 4x2, XLT Lariat, 302, 5 speed, 3.08
'99 Ranger, 4x2, 3.0, 5 speed, 3.73 posi

 

They didn't make the 351M in '73 or '74 and every piece of information I've seen says those are 400 engines tho' of course one could be rebuilt into a 351M. Casting # is D3AE-B. Why would a bellhousing bolt pattern not be "as strong" as any other? It's the same pattern that's been used for the small block engines for years.

 

Here's a newbie question. I just purchased a '94 F150 with the 5.8L EFI engine, it's not "HP". Which 351 is that, C, M, or W ?

Thanks

 

W

They quit making the Cs in 1974 and the Ms in 1982.

 

Thank you, Bill

 

Bill,

Good question, maybe I should have explained or not mentioned it. Size or specifically diameter to resist twisting forces. I didn't personally see this but a friend told me a couple of years after it happen to him in his '65 F100 sand truck. It had one of those 400s with the small block bellhousing pattern. One of the bellhousing ears broke (and other damage I don't recall exactly except it had to be towed back) and he had been warned by the machine shop that the engine would over stress the bellhousing if he didn't run a block plate or a tight engine tie down strap. He didn't do either obviously. His was the first really hard running 400 I had encountered.

Bob
'66 7 Litre, top loader, 3.25 Traction-lock, Sidewinder Intake, SCJ Exhaust
'88 F150 LWB 4x2, XLT Lariat, 302, 5 speed, 3.08
'99 Ranger, 4x2, 3.0, 5 speed, 3.73 posi