Quote Originally Posted by Oldf100fordman
Actually there were 3 351 blocks. The 351 Windsor, the 351 Cleveland (1970-73) and the 351 M. The 351M is the same block as the 400. The Windsor and the early cleveland used the mounts that were the same as the 302 and a bellhousing that was the same as the 302. The 351M and the 400 use the big block bellhousing and they have the same mounts as each other. If you really want to get confused, the FE series (352-427) had totally different mounts and bellhousings than any other series. Makes engine swapping a lot more difficult than on Cheebies.
technically there are 4 351ci ford V8 engines. all had a 4" bore and 3.50" stroke.

1: the 351w(the second 351ci V8)

2: the 351c(the third 351ci V8)

3: the 351m(the fourth 351ci V8)

4: the 352fe(the first 351ci V8)

and actually all displace 352ci, but when fron brought out the 351w in 1969, they called it a 351 to avoid confusion with the 352fe big block.

thesals, the 400 is a good platform to build a decent engine with. cams are the same as the 351c, as are the heads. in fact hot rod magazine built a 400 a few years ago that made 385hp iirc, and mounds of torque. cost? about $2000.