Had a good post going about shock extensions and what they do, but it was in the wrong forum so Ill bring it out in the proper section: Shock extensions were used to extend a stock rear shock length to deal with SS springs or shackles, increasing the static distance between the rear axle and the upper shock mounts while using a stock length shock. When a SS spring or shackle suspension is at rest, the stock shock is very close to its maximum extension. Any appreciable rebound, and the stock length shock will hyper-extend and lock out before the axle reaches its natural rebound limit dictated by the springs, ie. going over a speed bump or railroad track at speed. It will make a terrible noise under the rear seat, like someone hit it with a sledge hammer. With extensions, you are getting the shock length back into its stock working range. They provide no lift by themselves, neither do any hydraulic shock. Pneumatic lifted shocks do assist in load leveling but should not be used to raise the rear of a Mopar as the upper shock mounts are not designed to support weight as their primary duty. You can use a longer shock (Chrysler Imperial was suggested) and get the same result.