Strange torsion bar issue on my 1965 barracuda. Please Help.

You can't expect to see instant height changes when turning the adjusting screw. And measuring from the ground to the body is not how you measure ride height. Read the Factory Service Manual for a description of how to measure ride height, and how to adjust it properly.

At the very least, you need to bounce the front corner hard on the suspension 3 or 4 times after every adjustment, to give the rest of the suspension a chance to settle into the new height.