tire size
You can go with a 35x12.5x18 on the stock wheels or aftermarket wheels with close to stock specs. Stock wheels are 7.5 inches wide with a 5.5 inch backspace. On the stock wheels they may rub slightly on the upper control arm but nothing too bad. A lot of people run the 35's with no problem's.
You can take a little bit of the rub away by changing up the backspacing with aftermarket wheels. But I had gathered that you could run 35s on a truck with a 2.5 inch level kit without rubbing (?)





