I am in the process of doing a 2/3 or 2/4 drop on the Yukon, still undecided. Really don't want to cut into anything so wondering if the travel mod is necessary? I've heard that with a 3" drop it's not needed but a 4" drop it's almost required? I have the shorter Belltech bump-stops as well as Air-Ride with the Max-Trailering. Also curious from people that have done it if 4" is to much when you still plan on hauling stuff a lot.