I have an 85 Cutlass with a Moser 9" for G-Body. Currently I an running a 7" wheel with a 28X9X15 M/T Slick. The car makes 800hp and I wouls like to run a 9" wheel and 28X10.5X15 tire. It's extremely tight now. Does anyone have any information on wheel offset, and wheel well mods I need to do without hacking up the car? Thanks...