GEN V 502 Heads on 454 MPI
 

Two question. First off, will a Gen V 502 heads bolt-on to a Gen VI 454 MPI?
Second, does it offer any performance benefits? The particular heads in question are Mercruiser "Hi-Perf" heads.

Re: GEN V 502 Heads on 454 MPI
 

The combustion chambers on the Gen 6 MPI heads are about 98cc. The MAG Rec port heads are 118cc. You would not want to change them. Also intake would not match up.

Re: GEN V 502 Heads on 454 MPI
 

There are several things to look at/clarify before you do this. 1st are both heads square port? If you are changing to the square port head I don't think you will see any difference because the cam & compression is so conservative on the non-mag motors. The other thing to look at is a gen 5 head will fit a gen 6 block, but I am not sure about the coolant passages lining up correctly. I think they do. If I rember right the gen5 & gen 6 heads are interchangeable between generations, but they will not work on mk4 blocks without coolant passage modifiers.

Re: GEN V 502 Heads on 454 MPI
 

Thanks very helpful. I was curious more than anything else. Obviously, not very familiar with large blocks.