Does a duramax 2500 HD have a posi rear end?

The Duramax 2500 HD typically comes with either an open differential or an optional limited-slip differential, often referred to as a "posi" rear end. Whether a specific truck has a limited-slip differential depends on the trim level and options chosen at purchase. It's important to check the vehicle's specifications or consult the owner's manual for confirmation on the rear end type.