I did really well buying and using used shocks for my Houdaille needs. Takes little time to determine how much they leak. If you have no trouble making a bigger deal out of the shocks, then go for the rebuilts. amazed me how many correct '40 shocks show up at the swaps. I have purchased "rebuilt" units with only modest success. Fun exercise to flush old ones and see how they work. Commonly recommended fluids seem to low viscosity. Big spenders, disregard. Fred A