We traded in our 02 1500HD 4X4 and bought an 07 2500HD Z71/4X4 diesel. We had to under-sling the axles the 5th wheel to have clearance over the truck bed, and then I fab'd new shock brackets for the trailer. I would have preferred to lower the truck but I did not want to do anything until after the warranty runs out. We will see hao it goes through the mountains in PA this winter.