the ZC and the Z6 are gonna be the same price for me to purchase. i know the heads on these motors are the same so replacement parts will be no problem as far as plugs and wires and stuff like that. and also my D15B7 manifolds will bolt right up to the JDM D15. I'm doing this swap on a budget. i will be replacing the necessities like clutch, timing belt etc.... and my fly wheel will also fit. And as for the Y8 its still alittle to expensive cause its still a new motor on the market. but im still trying to figure out which motor is ultimately the strongest overall.