Getting ready to tune a buddies 2000 firebird. He bought a 427 ci LS2 with Mast Heads and a pretty big cam (apx 242I 250E). Car is an automatic. It has a 102mm cable driven TB. I was thinking we might just go SD because of the cam and the fact that he doesn't have a big MAF yet. I was going to upgrade the car to a 2002 OS because it doesn't use the secondary VE table and High and Low octane tables would still work. Would I be better off going to the 2002 OS or would it be better going to a custom OS. I know it has a TPS VE multiplier that might be of some use. I have never tried to tune that table. How does one go about that? Any other advantages of one OS vs the other?? OR should I go to a 2002 and then apply a Custom OS to that? That would cost twice as much.