GM has used a couple different transfer cases in the full size trucks since 1999. We proudly offer parts for all of the New Venture units. In order to find the parts you need, you first need to establish what transfer case you have for your application.
To insure you get the correct parts, it is recommended that you look at the tag on your transfer case.
If it has a floor shifter you have a 261HD. The electronic push button units came in 2 versions. The 3 button unit is the 263HD. If it has 4 buttons with the auto 4x4 setting it is the 246. The 8.1L, with an Allison transmission, check your tag and go here.