yea, I've not heard of cam/rod or cam/crank clearance issues on 451s...it's not THAT much stroke! the bottom half of the 383/400 is the same as the 440, right? don't they use the same timing chains? the differences in the block are all at the deck height aren't they?

if they are the same, then there should be no reason why a 440 stroke would run into issues with the cam in a block with factory dimensions--or for the most part, factory dimensions.

I may be wrong here though on the bottom half of the castings being the same.