So i've got an 03 GMC Sierra 4X4 with 20" rims. I currently have 285x50r20 performance tires on them, and need an all terrain or mud tire for the driving i do. Looks like i have a couple inches of room to play with. My question is what is a good size, and a good tire for the value to fit on this truck. Anybody else with similar setup? I'm willing to cut bumper a little to make something fit. Any suggestions? Oh yeah, don't want a lift.