351c or 351m

[yeska68]

ON this forum i have only seen cars with the 351C and not the 351M. Why is this? Is the 351M not a good engine to buy and enhance compared to a 351c or are they they the same engine??

 

[LMan]

short version - 351M is a truck engine, provides truck performance. Not a good candidate for a performance car. The heads are different and quite restricted compared to a C.

 

[dodgestang]

ON this forum i have only seen cars with the 351C and not the 351M. Why is this? Is the 351M not a good engine to buy and enhance compared to a 351c or are they they the same engine??

351c - great performance out of the box, great build potential.

351m - not

 

[yeska68]

understood

 

[D.Hearne]

short version - 351M is a truck engine, provides truck performance. Not a good candidate for a performance car. The heads are different and quite restricted compared to a C.

Heads are not that different from a Cleveland head, the only difference is the presence of the smog injection passages in the "M" head. Otherwise they're interchangeable. The 351M is just a destroked 400, which is why they aren't used more, they don't fit the 67-70 engine bay ( spark plug access is nil) the motor mount bosses on the "M" block are unique, and the performance of the 351M isn't hardly what you'd classify as "performance" Best thing to do with a 351m is replace the crank & pistons with ones for a 400, making it a 400. And using it in a vehicle that was designed for the engine's size and motor mounts. Finding headers to fit it, in a vehicle that never came with one is also an issue.