I normally run a 275/50 on a 15x8 with 4" backspacing on the street. A friend of mine had these tires on the same spec wheels and is letting me give them a shot next time I go to the track. The part number on them is 3355R. My rear end, axles, steel drums, etc are all stock. I do have heaver duty springs in the back. I'm convinced it's the largest combo you can stuff under the car with no modifications to the fenders and maybe get away with little to no rubbing. I can't fit a pinky finger between the wheel and frame at the front and back on either side. My rear is very well centered with the frame. Thought I'd throw it out there.