The rearend retains the stock 3.73 gears and GM limited-slip differential. The Off Road Unlimited diff cover protects and looks good. The Tuff Country suspension is augmented by Air Lift air bags and EZ-Ride Concepts air-bag spacers. Shane likes to use the GMC to tow his ATVs to the dunes and also drives the truck off-road while there. The lower rear shock mounts that hang down probably won't hit any rocks in the dunes.