I install alot of lift kits on GM's and Ive eyeballed the rear steering set up on the quadrasteer trucks and It seems to me that if you install larger tires when you turn the will hit the springs. I contacted a couple of lift manufacturers about a 6 months ago and none new if there would be a problems in the rear. Also I have lifted all wheel drive Yukons and Denallis and have had problems with the abs and traction control activating while driving around corners and under moderate to heavy acceleration. It causes the vehicle to pull from side to side very fast. I have even used programers to change the tire size in the pcm to what is one the vehicle. The only thing that has fixxed this problem is to change the tire to a 33 or smaller. Almost not woth it to lift these vehicle and then put 33's on them. I have not had any of these problems on none all wheel drive vehicles. My 0.02$ :grinpimp: