Ford Muscle Cars Tech Forum banner

1 - 4 of 4 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter #1
I have a 78 (3-21-78) f150 custom that has a seized 302. I’m pulling that motor and have bought a 351m. Just wondering if that 351m will drop right in or will I need to make some adjustments.
164604
 

·
Registered
Joined
·
7,443 Posts
Nope! The 351M/400 has a 429/460 bell housing pattern, different motor mounts than the 302, etc. In typical Ford fashion, everything that CAN be different... WILL be different. The 351M is also highly inefficient in stock form. They don't make much power, and get horrible fuel mileage. To install the 351M, you'll need a complete parts truck from the same era.

This being said, a 351W will bolt right in place of the 302. You may have some stuff on the front of the engine and exhaust to work on... but that's the best swap, if you aren't interested in stabbing another 302 in it. A 351C will also bolt in place of the 302, and shares the same motor mounts and bell housing bolt pattern.

This being said, if you swap another 302, make sure its a 1981 or older. The newer 302's are balanced differently, and use their own harmonic balancers and flywheels with a bigger external weight.

All 351W and 351C engines have the same balance as the older 302.

Good Luck
 

·
Registered
Joined
·
3 Posts
Discussion Starter #3
That’s what I thought. And the 351m I’m getting tomorrow was built for truck pulls.
 

·
Registered
Joined
·
7,443 Posts
That’s what I thought. And the 351m I’m getting tomorrow was built for truck pulls.
If the person you bought it from had any brains, it may be a 400... as the only difference between the 351M and the 400 is the crank and pistons. Therefore, at rebuild time... those are the ONLY two items it takes to convert a 351M to a 400.

TMeyer has a lot of parts for these engines. At one time, TRW forged flat top 351C pistons were cheap, and have the same compression height as the 400 pistons, but a smaller pin hole... but you could bush the rods down smaller and use them. TMeyer has all that stuff covered nowadays. They are a 351C/351M/400 specialist.


But, if it hasn't been done already, all you need to do is find a 400 crank, use the right pistons... and you've got 400ci.
 
1 - 4 of 4 Posts
Top