Originally Posted by ncg11
sorry lol 4 inches total 2 suspension 2 body. it seems to have vibration only when I first take off. but then it goes away
Yeah, that's because the driveline is shifted a little with the lift AND I'm betting you probably have some worn out rubber bushings in the rear control arms. That would allow the axle to move a little bit and the u joints will setup weird harmonics when you take off; It probably does it under load too (accelerating) but you haven't noticed.
If you replace the bushings and the vibration is still there, try these out;
Basically you drill an oval hole in the upper control arm mount and then you use the cams to tip the pinion a couple of degrees. You should not need to max out the cams you only have 2" of lift with the standard driveshaft. The goal is to match the u joint angle with the rear u joint angle; ie if you have ~10* of angle at the transfer case, you want ~10* at the pinion. If you have questions, the tech guys at Quadratec are very helpful.
Be warned, once you drill to install these, you'll always need those type of bolts (actually the disk on the outside) unless you get someone to weld the hole or make a new upper control arm bracket. Adjustable upper control arms are nice, definitely overkill here, but there is no precise drilling required and you can always go back to stock.