What are the largest tires you can fit on the stock 17" wheels supplied on the 05 Supercrew without rubbing or other issues?
I have 255/65/17 Continentals on there now, but looking for some more height through 285/70/17 or other?

 

Do you have a 4x2 or 4x4? If you have a 4x2, you will probably have to add a leveling kit to the front to clear 285/70-17's (33x11.50). If you have a 4x4, you can fit 315/70-17's (35x12.50) with a leveling kit and stock wheels. 285's will fit a 4x4 easily with no lift at all.