The ride height specs would come from the "V and L" lines in the shot from the FSM I posted. They didn't change from year to year.
As for the torsion bars, you can just measure the diameter with a set of calipers and be in the ball park. If the car is constantly sitting on the bumpstops though the bars could be worn out. The original bars are over 40 years old now, so really they should be replaced if any kind of serious driving is to be done.
