Hey there. I just mounted on my new Weld RT-S rims this morning. In front are 15x6-5x4.5 bolt pattern, 3.5 inch backspacing with 196/65R15 tires. In the rear are 15x8- 5x4.5 bolt pattern, 5.5 inch backspacing(due to B-body rear end) with 275/60R15 tires. Hope this helps!