Ok, I've done the searches. I know that the the 4th gen axles petrude out 1 1/2in on each side and that you need a proportioning valve to swap it and that all third gen surrounding parts bolt up. But here is my question. From the looks of 4th gen rears on other cars, the tires look even with the 1/4 panel lip. If you hit a bump, will it touch? I don't know if I'm saying this right but it looks like the tire could mess up the 1/4 panel. Any input would be greatly appreciated.

 

It reall depends on what wheel you use. You can run a 4th gen rear and with the proper back spacing keep the tire tucked under the quater panel. Your bump stop should prevent any damage to the quarter panal if you are running really tall tires that run flush with the outside.