I have a 71 Duster that I completely rebuilt. My question is when I set my ride height with the torsion bars and then go for a drive and when I get home the car has dropped 1 to 2 inches. I have reset them 3 times and the car still is lower after I drive it. Does anybody have a answer?

Yes. It's called loading. You cannot pre-load the spring when you adjust it in the air under no load. After you drive the spring will see real load and compress down to it's natural load.

So after you drive it adjust it up or down. Then drive again and adjust again until you get the height you desire.

So what you are saying is to set the ride height with the weight on the tires? and not have it raised all with a floor jack.

when I did my car, I went by the factory service manual where it said to take the measurements from the pivot area on the control arm to the lowest point on the ball joint to the ground. I think the difference between the two was supposed to be 1 7/8" +/- 1/8". Once you get that, you are supposed to "jounce" the car (I think its a form of bouncing) the car up and down a couple times to get the car to settle. I held onto the front bumper and did this. It took me a couple times of doing it but I finally got it dialed in only to take the car for a ride and have to reset the adjustment again.

Yes - that will get you a more accurate starting point

Correct. Be sure to keep the nuts for the pivot spindle loose otherwise you could tear the lower control arm bushing. Been there, done that.... would have gotten the t shirt if there was one. lol

Thanks guys I hope this fixes my problem its driving me CRAZY (I know its a very short drive)