I have my hands on a '74 351m short block, so I was told. It has been built and all. What is the difference in the '74 and earlier 351m against the '75 and later 351m? Need to know ASAP! I pick up motor Saturday afternoon.

 

There is no such thing as a 74 351M, they weren't made until 75. The 400 and 351M are the same block, and if somebody has swapped cranks it'll eat bearings unless they had it align honed and bored, which they probably didn't.

 

I have been reassured it is a '74 351m. the man i am getting it from called Ford in detroit and he said they verified it is a 351m. I thought it should be a 400 as well. I am still going to get it and run it in my wifes truck w/ 4v heads and spacer plates