Most of the frame mounted lever shocks are "single-acting"- - - -they let the spring compress with little or no dampening, and try to control rebound. Tubular shocks will have dampening action in both directions- - - -some with a 50/50 jounce/rebound proportion, others 70/30, etc. or something in between. There was even a 90/10 drag racing front shock at one time that allowed the front end to rise quickly on acceleration, and held the front end up all the way down the strip for better weight transfer to the drive wheels. Obviously, that was not good for street use!
Jerry
