they are adjustable ON the TJ...?I would suggest Nth Degree uppers. They are adjustable ON the vehicle. Makes life a whole lot easier.
to better answer your question you need to set the pinion angle down roughly 2 degrees below the drive shaft. That will allow for the bushings to flex and stay away from vibes. I use a dial indicator and place it on the pinion housing and along the body of the drive shaft.how do you set the pinion angle i just got at cv drive shaft and sye i have a 4in rough country lift