torsion bar questions

I have a 72 scamp that everytime I lift it on the lift the right side always saggs afterwards. Also after time the torsion bar on the right side needs to be cranked up. The right side the adjuster bolt is almost at the endof its threads. The left side has about half threads left. Do I have a weak torsion bar? What makes them weak? How do I pick the right bar for my car? Im running a small block 360. I dont race just cruise around. It is a tubbed pro street. Do these torsion bars come out from the rear or do I have to remove lower a-arm and pull from the front? Thanks