This is my 20' with 6112s, and icon UCAs. I also did Clayton Gladiator springs and Bilstein 5160s in the back. I would say you do not need to do the rear end at all, BUT you will see a slight negative rake for the first few thousand miles (At max lift) until the springs and shocks settle in. Then you will level out. Until you put a couple bags of mulch in the back. Haha
The 6112s ride and drive really nice after about 2000miles on the setup. It was slightly more stiff than stock when we first got it put on but not noticeable now. No complaints from the peanut gallery.
The Clayton springs really help with keeping a positive rake and towing/hauling. I had full dirtbike, trailer SxS and 4 wheeler on the truck with very minimal sag. If that's not a concern then no worries.
This Tire/offset is too big (325/60r20 -44) needed a ton of trimming and an additional 1/2" spacer. Still rubs at full lock in reverse.
Hope that helps. Good luck
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