The rear of my car sits higher on the passenger side than the driver's. The previous owner used to drag race the car and I am sure the torque caused it to twist. What can I do to adjust this. I have just lowered the front 2 inches and was wondering when i go to lower the back if there is something I can do to correct the uneven height..... or would it possibly be the frame that is twisted? Thanks for any suggestions.

I have a similiar problem and there are several things that I think it could
be; one thing I've read it could be would be the front sway bar is loading pressure on one side try disconnecting it; another would be incorrectly seated front springs; and the last would be which I hope my problem is that the rear shackles on the springs were replaced and are too tight and not flexing and causing the side to side difference. I hope it's something like this.
Also, if any body panels were replaced they could be off and the frame could be in the correct position.

are the rear shackles supposed to be straight up and down or angled toward the back I have a similar problem and looking at the shackles the angles between the two of them is off?

The rear shackles were for the most part, straight up & down, maybe at the most, a 5* tilt forward.

Sway bar could be a problem and should be checked as stated.

As suggested later, check to make sure the body panels are aligned.

My suggestion is this. Set the car level and either remove excess weight, ie, spare tire, tools, etc. Bounce the car front & rear bumper several times.

Now sit in the middle of grille and the same height as the grille in front of the car. Look upon the car and take note of the the upper windshield molding and compare the parallelism of the hood to the roof and cowl panel. They all should be even.

If the left front corner is higher than the cowl panel, you might check the distance between the subframe to the floor pan under the seats. If you can slide your hand through the space, the subframe has pulled down the floor about the rear most bolt. This allows the left front corner to come up using the firewall bolt as a fulcum.

Also, check the body bushings are in good condition.

If the previous life of the car was a racer and it does not have subframe connectors on it, good reason the body may be twisted. There is no hope for a fix overnight, this body/frame twisting was a gradual event over time and any quick fix, such as using a frame machine to pull it back into shape will definitely upset it and could shatter a windshield and misalign doors and hood.

Or it could be one spring is weaker than the other. The ways to tell is either remove the springs and take them to a spring manufacturer to find the spring rate or swap sides and note the height difference.

My car had sa similar problem. It meausred 1/2 to 3/4 inch lower on the driver side rear. I replaced the body mounts as one was crushed, yes it was a drag car at one point in its life. It didn't change anything. I then measured all 4 corners and found the driver side front was one 1 1/2 inches lower. I installed a one inch spring spacer and solved the problem, since bringing one corner up brings the other corners level. Over the winter I instlled brand new stock z28 springs all the way around and didn't need the spacer. It now is within 1/4 inch all the way around.

Try unhooking both sides of the front sway bar and re-measure the difference. If it levels out, shim the driverside link a half-inch or so or trim down the passenger side spacer to keep it level. 1st gens don't seem to like to sit level, and an even, level stance is a must for me. (At the same time, I don't like to rig something to work right, but I'd rather have my sway bar end links uneven than the whole car!)

Measure all 4 corners. Do simple floor to wheel opening lip. Sometimes it is actually the front causing problem especially if as you explained you just installed front springs.