I have an '82 Camaro SC with a 350SBC. My timing is set to factory specs I belive, will advancing or retarding it make any performance difference, if so how much and how far should I go with it? Also when you put a supercharger or turbo on a car do you have to change anything else like the cam or anything? I was tempted to try to make either a twin turbo or twin supercharged system but I'm still a little fuzzy on anything but NA engines. On a Twin turbo car would I set both turbos at the same RPM or do I set one lower than the other to avoid turbo lag? And finally If I look for junkyard turbos to rebuild, what ones should I look for? one out of a but diesel truck, a little supra or what? Any help would rock! Thanks