the inside of the rotor isnt what helps to stop the car though, so whats the point?
I guess my point is if the caliper doesn't reach as far down the rotor, the stock GP caliper wouldn't have the same contact patch as if the impala/f-body caliper would. That would mean swapping calipers would make it better than not.
2001 Grand Prix GTP - Daily Driver12" front brake upgrade ('05 Monte), Raptor tune, Open cone, Front and rear strut tower braces, SS brake hoses, BMR trailing arms, ZZP 3" catted downpipe, Dorman front sway bar, GMPP rear sway bar, solid trans and engine mount, flipped dog bones and Borla exhaust.