Well i did it they other night I got tired of my rear wheels rubbibg the fender wells all the time. I am running 285/60/18 a/t so I knew I would have some issues. I put a three and one half inch rockkrawler lift on it with a rear spacer now. The spacer brought the rear up about another 3/4 of an inch. And no I do not have any driveline vibration. I walked it up on a hill at the house and the only spot I rubbed was on the rear of my fender wells. I think I can fix that by shortening the adjustable control arms on the rear. I gave them one turn the other night because I was not sure how much that would do. I t did not due enough. It is a balancing act because if I draw them in too far they will rub the front. I do not reccomend 285 wide tires they are a pain to adjust and tweak until they fit. The next thing that I will be doing is installing bump stops on the coil bases, I saw somebody on here had done taht and it looked pretty simple. I took the libby out yesterday to check my game camera and it crawled right thru some pretty good wash outs so I am happy with the Lift too. I will say that you have to get used to the clunk from the front sway bar exentions but overall it has been great. I will attach pics this week and yes the so called rap mobile does get dirty I will have proof real soon.