Its always when you change the stock height of something you need to change the shocks most of the time but (some exceptions come into play). Here's an example lowering the rear with a 4" drop springs using "Nolimits shock relocating kit they recommend using there "A" length shock witch is 12.75" closed, 21" open with a ride height of 17" +/-. that being said the stock OEM shocks would be a little bit taller (just guessing here) at stock 13"/14" closed, 22"/23" open and 18"/19" ride height. Think of it this way you raise up a truck the shocks will also be taller than stock and lowering a truck you also need to shorten the shocks BUT when you re locate with new bracketry and use drop spindles these also will maybe change but most likely no change with drop spindles, now as with the rear changes springs, lowering blocks and relocating brackets also change things around.
Get informed with your trucks stock height or your vehicle's stock height then get the info from who's selling the drop springs, the relocating kits and drop spindles for what they recommend using for shocks wise.
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