Why does the left rear hang low ???

The lower control arms have a threaded adjuster that applies pressure to the torsion bar. They are located about halfway up on the bottom of the arms. You have to almost get right up under the arm to see them. Standard threads so turning it clockwise will run the adjuster in applying more pressure and raising it up. CCW will do just the opposite. After adjustment you need to work the suspension to settle it. I know there are specs for setting them up but I threw those out the window when I upgraded from 13" to 15" tires and wilwood discs. I just use the fender lip to the ground as a reference from side to side to set it up. I know there is a correct method to set up ride height but, this way works for me. It takes a 3/4" socket. Don't be suprised if the adjusters are hard to turn. I would spray them with some penetrating fluid first.