I have a 73 camaro that after installing 15x10 centerlines with 4 7/8 back space will hit the right rear fender lip on a hard launch. Bending the lip will not fix this much of a differance. I have measured both sides of the car and the right rear wheel is about 3/4" further out than the left one. I have since noticed that all the second gen's I have seen have this same issue. Does anyone know how to fix it?

 

You could install a spacer on the left side to make them equal, but moving the axle mounts would be the only way to make the difference up. That could be a pretty good weekend project if you've got a welder and torch.
PS- I just measured my 1971 and the rear axle is perfectly centered.

 

You might have worn out and collapsed leaf spring bushings which could be allowing it to sway that way.