Everything you mentioned differs between the two engines. Injectors, P7100 pumps, pistons, camshafts, and timing specifications are unique to the horsepower ratings of the various engines. The piston dishes are the same type, but ring placement is not. The 215s have steel ring land inserts for the top rings. I seem to remember the others did too; the 370 marine engine had steel for the top and second ring I believe.