It's amazingly capable as it is, but Crikeymike has it pegged.
2-3 inch suspension and some light trimming will get you up to 31 inch tires. Add a Locker of some sort in the rear, and go wheeling. Just a locker and decent tires will get you an incredible amount of places.
I surprised myself with 29" tires (235x75x15) and a 2" suspension when I first started out. Surprised some Jeep guys too...