I have a 2004 GMC Sierra ext cab, stock. Will 17" x 285x70 BFG Mud terrain Tires fit on the truck without any modifications or will it have to be lifted or something? If they wont fit then what tires would fit without a lift, and still look good..

they'll fit... you might want to turn up your torsion bars just a little (like 2 turns) but they will fit.