I have a 1976 f-250 with a 360,i'm installing a 1963 390
with motor mounts 2 &1/2 inch apart,will i have to
move,fabricate,or drill frame mounts,or motor mounts
from my 1976.please help!!

 

This is probably a better question to ask in the FE forum. The difference in motors mounts is a well-known thing there.

I'm going to hazard a guess and say that the motor mount holes on the 1963 390 will NOT be in the same spot as the '76 360.

Not sure what you can do about it. I've heard that swapping motor mounts from side to side makes up the difference, but not sure if that's a real solution.

 

Dust, IIRC, you can drill two new holes in the motor mounts. If you use the '76 block as a guide, you should be able to see where to drill the holes. The later FE blocks have four motor mount holes, the extra pair of holes match the holes in the earlier blocks. DinosaurFan