Question reguarding backspacing....

I'm trying to decide on the proper backspacing on a set of wheels to order..
My 96 Xj with stock 15x7 steelies and new 30x9.5x15 BFG A/T ko's, when I make a hard right or left turn, it sounds as if the the tires maybe rubbing the lower arm.... I would like for the tires to sit a bit further toward the exterior of the wheel well and away from the suspension components....
any suggestions on what backspacing I should go with?

4.5" would work great for you

Unless you are dead set on buying new wheels, you can minimize the rubbing by adjusting the steering stops. (you may need to get a longer bolt, but it's been so long since I did mine I can't remember if I did or not)

I ran stock backspace and 32's for 2 years with only minimal rubbing at full lock.

Enjoy!