[KobraKarl]

Zimmy,

cranks for an early top oiler are almost identical to390 crank(both are cast), same goes for rods.

390 pistons would never fit in a 427 block , the bore for a 390 is.18 smaller.

check your block for casting # pasenger side on # 1 cylinder

check your head casting # as well

I have recieved an education on low rise / mid rise manifolds on this forum recently and have discovered just how badly these bolt on parts can be mis-matched, your ida's may not like your low rise heads at all, also manifold and /or carb. air leaks call for a rich tune, that will never run right .

let us know what you find ,you might be better off than you think.

Karl