I was very pleased with the Western Chassis kit on my truck. I had 2 sets of their control arms. The second set had an revised and improved design. You can get anything from a 2" rear drop to "level" the truck all the way up to about a 6/8 and still be driveable, even on 20s.
I actually still have the majority of my kit, and am not using it. Unfortunately it is sitting in a box up at a shop in Sacramento, and I don't care to drive back up there any time soon.