Reply to "351C Blocks"

All 351-C blocks are identical and were made 1970-1974 only, so hike out to your local wrecking yard and find one. The 351-M will not work, nor will the 400-M as they use big-block bellhousing bolt patterns so the ZF won't bolt up (there are internal changes too). Easiest way to tell a 351M from a 351-C is to span the top 2 bellhousing bolts: in the M, its over 8" apart (the max span of a normal human hand) while the C is much narrower. 351Ws have the removeable front cover so that narrows down your search. Most wrecking yards guarantee blocks to be uncracked, but as to whether they're useable is another story. A lowly 2-bolt-main block out of a wrecked station wagon will be as good as a 4-bolt-main block out of a Mustang, so don't spend too much. A tear-down at the yard may be the best bet. Pistons are stamped on their tops with any oversizes; take a carbon- scraper to see the stamps.