you will feel a difference w/ a locker in the rear, it may lock up on turns and you will have to either slip the clutch or power threw, i would suggest, just a front locker, becasue in my expierinece it is usually the front that spins
i would get a front one and wheel it likethtat for a while, and if you find your still getting stuck either buy a rear locker, or get a winch, personally i would go with a winch becasue it will get you out and it will not decrease the on road ability of the truck