[b454rat]

I think the wheel wells on the 67-72s might have been the biggest GM make. 60-66s are huge too. I had a 62 burban that had 35s on it, all stock.

The rear is never a problem. The 89 GMC SAS I built had 40s on the back with no lift. It depends on what brand and size of tire it is, also the rim width and b/s.