So I just finished installing a 1995 Z28 3.42 posi rear end in my 91 Z28. Everything went fine, until I lowered the car. Now I dont know how the wheels lined up before, but now the drivers side sticks out MORE than the passenger side. I know that the wheels will stick out more after this install, but what I mean is that its not evenly sticking out. From my measuring its almost exactly a half inch offset to the drivers side. What the hell happened? How can I adjust the rear end? This is probably related to this problem but when taking a left hand turn the drivers side rear disk brake hits the brake pad making an aweful noise. I need help!!!

are your control arms stright??

i think the panhard bar is what centers the axle IIRC

so i would have to check that out maybe

Everything measured nearly perfect when I jacked the rear end up and adjusted the springs so that it points the front of the car. However when I bolted on the panhard bar at the highest point (rear end touching the rubber pads) and then lowered it again it looked and measured fine. I took it around the block and when I got back the whole thing was out of whack again, not by much, about 1/8th of an inch, but what the hell? Is it possible that I bent something along the lines? I have a 400hp engine but I dont see how that could have bent the panhard bar, maybe it could, Im new to this.

89RS is correct when he says that the panhard rod has an effect on the centering of the axle. Because of its design youll notice that because one end is bolted to the axle and the other to the body as the suspention travels the panhard rod will force the axle to the left or right because again the axle cant simply move up and down if the panhard rod is bolted to it and the body it will be forced to move in an arc. That being said the ride height will have an effect on the axles location. In your case ide say your rear at least is sitting low causing the panhard rod to push the axle out to the drivers side (assuming nothing is bent). This could be caused by lowering springs, the insulator under the coil springs being smaller, worn springs, ect. Long story short ide check your ride height against factory specs and compare measurements from axle to axle (to ensure nothings bent). If anythings bent or the cars been in an accident all this kinda goes out the window so to speak.