More than likely, the previous owner installed installed a lift. With that size tire, you will eventually rub in at least two locations -
1. Wiring loom along the frame well at the front, drivers side wheel location. Turn the wheel hard right and look along the frame. If you rub this loom and break any of the wires inside, the rig's suspension essentially dies and you will be stranded. Simply relocate the loom higher up on the rail so it doesn't rub.
2. Rear body seams that protrude into the rear wheel wells at the front of the rear tires. Look at the wheel well liner and you will notice a square protrusion that stands "proud". Behind this liner, the body panels come together and will rub the tire under compression. Either grind it down, hammer it over or trim it off (not completely).
You can always drop down to a smaller sized tire or plan to add a lift of some sort. Do your research as there are numerous lifts and software reprogramming options out there. Good luck. Enjoy the new rig!