My 2 on the choice of heads... I would stick with the LS. Cam it, double springs, Ti retainter, ect. Vtec is best for NA. From what i looked into, turbo cams i have looked at for vtecs actually elliminate the 3 lobes stepping, giving 3 lobes of the same size. Duration might differ, but size looks damn near the same. I didnt get to measure with a caliper, but they look DAMN near the same. Im building up my b18 for boost, and im keeping the LS block and LS head.