Word on the street has it that you'll be wanting the
2" leveling kit..... not the 2.5" kit, with a 4x4. The 2.5" stands a 90%-100% chance of causing you to hit the coilbuckets with the UCA on full droop, or when you go over decent bumps. The 2.5" kit is for the 4x2 trucks.
Here's my truck way back when... in the good old days... with the PRG 2" leveling kit:
Oh, and here's where you can go to get it.
http://www.prgproducts.com/shop/prod..._leveling_kit/
One of the easier and most satisfying mods you can do!