Differences between 351c and 351m

[CoolDansta]

Can someone please help me out? What are the differences between a 351c and a 351m and what are the specs of these two engines

[dodgestang]

351c - good motor, lotsa potential. Uses same bellhousing bolt patterns as 351w, 289, 302.

351m - destroked 400, uses bell housing bolt pattern as 390, 427, 428, 429 generally recognized as a boat anchor (aka not a very common platform for performance motor setup)

[Maxum96]

351C and 351M look virtually identical. Same design, same heads, etc. The 351M is is an inch taller in the deck height. Crank is different than a 351C. Intake manifold is wider than a 351C. A 351M and 400M are the same engine, just the 400M has a longer stroke. 351M uses 429/460 motor mounts and bellhousing pattern. You can not easily put a 351M/400M into a vintage Mustang. There is zero performance support/parts for those engines. It's basically a smog motor Ford came out with to bolt up in place of a 429 or 460 for early to mid 70's Ford cars and pickups.

[beechkid]

Originally Posted by Maxum96

351C and 351M look virtually identical. Same design, same heads, etc. The 351M is is an inch taller in the deck height. Crank is different than a 351C. Intake manifold is wider than a 351C. A 351M and 400M are the same engine, just the 400M has a longer stroke. 351M uses 429/460 motor mounts and bellhousing pattern. You can not easily put a 351M/400M into a vintage Mustang. There is zero performance support/parts for those engines. It's basically a smog motor Ford came out with to bolt up in place of a 429 or 460 for early to mid 70's Ford cars and pickups.

Agree!! also the power band is higher in the C than the M (with the windsor being - all things being equal- being the strongest street engine of the 3)

[69DroptopGT]

Yep. Do not waste time with 351M. Useless engine. The 351C and Windsor are way better (cleveland is best b/c of heads). 351 C has some problems as far as oiling and bearing but a great engine. 351 W nice engine but heads are not that great. Put some aftermakets on them to make go nice. Or make a clevor which is 351W with Cleveland heads.

[fordguy]

Originally Posted by dodgestang

351m - destroked 400, uses bell housing bolt pattern as 390, 427, 428, 429

FE and 385's have different bell patterns. the "m" uses the 385 series bell pattern.

[rickgto]

The "M"odified Cleveland was a highly sought after engine by scrappers. Very heavy.

[bartl]

The "M's" were designed as replacements for the FE's in full-size cars and trucks to meet the Federal emissions control requirements of the early '70's as it was deemed to expensive to modify the FE's to comply. The heads are NOT exactly the same as 2V "C" heads, having a chamber a couple cc's larger. The 351M/400M has a larger main journal diameter (3") than the "C" and a 1.1" taller deck. The only differences between 351M and 400M's are the crank and pistons. Everything else, including the rods, are the same. Years ago it wasn't possible to do much with these, but with the aftermarket offering an aluminum 4V intake it DID become possible to get some power from these but most application see them in trucks.