Yes your measurements are correct. The stock steel rims are 15x6, with 5.5" backspacing. I put on a new set of 215/75/15's on some black Cragar style D-window rims and the rear was fine but the front was a no-go. They were 7" rims with 3.25" backspacing. It pushed the front out too far and the tires hit when you turned the wheel. They looked so good, hated to take them off but since I actually want to drive the car and not just display it in the front yard, back to stock rims we go. I looked at all kinds of non-jeep options and the closest you'll find are some FWD rims when it comes to that much offset. But the problem there is the choices are mostly asian rims, not something offroad worthy. But, I'm still looking............