Ok, I need to ask you, why the 4:10's or 3:90's ? Also, which would be better, a 1050 dominator(9375) or 2-750 Dbl pumpers ? One more, I really don't want to cut the heads or the block for o-rings, what is a good head gasket ? Thanks for you help. The crane cam you mention is just about where I want to be.