[olddog]

From what I have read, Ford changed the firing order on the 351 to lessen loading on the main bearings. Some 302/5.0 engines used the 351 firing order while others stayed with the old firing order in the same year. It seems like the later 5.0 all used the 351 firing order, but I don't trust that memory.

I've heard claims of Hp differences, but never a controller dyno test to prove it. Love to see one though.

If you are running multi point EFI it matters, otherwise I doubt it.