Originally Posted By: DSparks
351c has nothing to do with a fe390/427/428 stuff.....351c is a small block with canted valve heads that came from the Boss302 that had canted valve heads similar to a 429/460 .it was fords performance 351...it came with 2 barrel(2v) and 4 barrel(4v) heads..it was basically a 351 cubic inch version of a boss 302 which is a specialty 302 with the very similar canted valve heads for the 69/70 mustang and a couple cougars...the 351w is nothing more than a stroked 302....the 351m/400m are the total [censored] of the bunch..still small blocks based on a 351c..same 2v heads and little different block/crank/stroke...im a ford guy..been there done all this ..got the t-shirt...
The 351W is not a stroked 302, as the deck height is different as is the main bearing size.
The rest of it is pretty much on the money for the most part though
The 351W and 351C were very different engines. What they shared was bore spacing and head bolt pattern.
The 351W was a "low revving" truck engine (not really but that's what it is often referred to as). The heads fitted to it were usually of the asthmatic type and the large 3" mains meant that the RPM range was limited over its smaller main bearing brothers, the 302 and 289.
The 351C on the other hand (and the 335 family in general) were smallblock derivatives of the 385 family sharing the same style of canted valves in the heads and robust blocks. Many of them also had large 4-bolt mains. The actual main bearing diameter was smaller than the 351W.
The 351C had a dry intake with the coolant neck coming out above the timing cover. The 351W has the neck on the intake manifold and has a wet manifold.
The "M" engines, the 351M and 400, were derivatives of the Cleveland. They had a taller deck height (like the 302 vs 351W) and the same size (3") mains as the 351W. This family of engines had the big block bell housing bolt pattern, unlike the 289,302,351W and 351C. Which allowed them to be a direct replacement for 385-series engines. They were all of generally low performance.