451 is a 400 block, 60 over K&B pistons, 440 rods, 440 cast crank, I have read the block is stronger on the 400 and is 65 lighter than the 440, Ok 440 motor has a K&B stroker crank (it's my understanding it has a 5/8 longer throw)than the stock 440 crank, Hemi rods and 400 pistons, as for the...