Duster - Suspension/Wheel/Tire Combo Question

I need help in determining if the following wheel and tire set up will fit under my stock 73' Duster rear fender and not rub against the stock located CalTrac leaf suspension. Any help would be appreciated. My concern is that the 4.875 backspacing might be too much and cause it rub against the leaf springs. Thank you.

Wheels: Centerline 15x8.5" with a 4.875 Backspacing
Tires: P275/60r15