Many units have a "built-in" lean. One side is heavier than the other due to the way the slide outs are loaded. Typically, the kitchen slide side is 800-1000 pounds heavier. My rig sits 1/2" to 1" lower on one side due to this built in weigh bias. This makes it very close on tire clearance on that side. Since I wanted to put on slightly larger tires, I put lift blocks on the rig. On the non heavy side, I went with 1" lift blocks, and on the other side, I went with 1-1/2" It leveled me out and gave me the clearance that I needed for the G614 tires.