well heres the story, when they first started putting the 302s (5.0s) back in the mustangs, i think in 1979 they started using weaker (cheaper) blocks. Ford racing performance parts says not to build a stock 5.0 to more than 450hp. Not that youll have that problem. Depending on the crate motor you get, it might be the same block. From ford racing you can get crate motors with the sportsman block, which can handle 600 horses or you can get aluminum blocks that can handle 1200... theres something for everyone. So i guess if it were up to me i would get the crate motor, it takes the guess work out of it. Just do some research.