I just read on another post that some guy with a C4 vette gained 15 RWHP going from 1.6 to 1.7 rockers. Stock heads can handle .600 lift. I already have Comp 1.6 pro mags, but I won't rule out 1.7's. I figure the valetrain set up I'm currently looking at would easily handle the extra lift. Just not sure if I want to bother though.