Nov 18, 2008 · Today, we can build a 351M/400 with a 4.75" stroker crank and a 4.060 bore to displace 492ci. This is what's feasible. What's economical has mostly to do with aftermarket support.

Jun 7, 2022 · The 351M has a displacement of 3.8 liters while the 400 has a displacement of 4 liters. Both produce approximately 300 horsepower, but the 351M produces about 150 horsepower more than that of the 400.

Jun 29, 2015 · 351M/400 engine supports and rubber motor mounts are different than 360/390. I'm not a fan of 351M/400's as they were very prone to cracking cylinder heads. We would love to put the 390 back in, but it is gone, and finding one around here is hard.

May 27, 2003 · The 351M/400 block is an "overgrown" Cleveland with bigger mains and an extra inch of deck height. BTW the 351W is an "overgrown" 302. The 400 was first introduced by Ford in 1971 while the Cleveland was still being produced and used Cleveland 2V heads.

Mar 30, 2003 · 351M vs. 400M the only real way to tell the difference is to check the part num on the chrankshaft. the harmonic balencer is thicker on a 400. a 1k on the crank is a 351m. the 400 was made from 1971-1982, the 351m was made from 1975-1982.

There are 351M's and there are 400's, but no 400M. A little background: Ford didn't put a letter on their engines, like 351C, unless there was more than one engine with the same cubic inch displacement.

May 12, 2008 · one way to see the difference between a 351C and a 400 or 351M is the thermostat housing sits up about a 1/2 inch from top of the block on 351M/400 and on 351C the thermostat housing sits flush to the top of the block.

Jun 24, 2007 · The 351c, 351m, and 400 engines are all part of the 335 series engine family. What distinguishes the 351m/400 blocks from the 351c is they have 1.1" taller decks and the 429/460 bellhousing bolt pattern as previously mentioned. 351m and 400 engines are built on …

Feb 6, 2011 · Since the crankshaft is the main component that determines whether the engine is a 351M or a 400, the only reliable way to identify an M-block engine as either a 351M or a 400 is to verify the crankshaft casting ID code.

Oct 29, 2006 · The 351M/400 were poor performers in stock trim, with restrictive intakes and poor cam timing, but there is no reason that can't be fixed with a rebuild. The stock 2 barrel heads are fine for a mild engine, although the open chambers are prone to detonation. 4 …