Fits a 2013 Chevy 2500HD 6.0L with Long Bed and Standard Cab. Length, offset orientation and inlet/outlet diameter are perfectly matched. The 2500HD will have some differences in exhaust layout between the cab and body layout, but this is perfect for the long body of the standard 6.0 liter cab. 2011-2014 everything should be the same. I cut about an inch in front of the muffler and about an inch and a half from the rear hanger behind the muffler outlet. This muffler was worn directly on the…