I dont think your gonna like to runb that wide a tire on that size rim. A 28x10.5 slick or 28x12.50 etstreet will be just about all you could run for cruisin out back. and a 15x10 rim will need atleast a 6.5 backspace but 7 would be better. I like the way a 275/60/15 drag radial looks on a 8 inch rim.