Got a question regarding shocks for lowered F-150's. I'm dropping my '90 F-150 extra-cab with 1 inch lower (actually 1.5) Eibach springs and 2 inch shackles(Don't want the "slam" look, been there,done that). Do I need to put a "drop shock" on this or can I get by with original length? I need new shocks anyway so the cost isn't an issue. Tahnks in advance.

 

The key to new designs with shock absorbers is that they don't bottom out with the suspension fully collapsed and that they don't top out with the front suspension hanging free. A margin of clearance at both extremes is desired (about an inch at top and bottom) Set your truck at the desired ride height under your anticipated operating conditions (load etc). If you can still use the OEM mounts for the shocks measure the distance between the centerline of the top and bottom mounts (oplength). Next, measure the distance required to bottom out the suspension with the frame bump block (complength). If this is a rubber bump block count on 75% compression of the rubber. Next, raise the vehicle so that the front suspension hangs free with the tire off the ground. Measure the distance between the top and bottom mount centerlines (maxlength). Some suspensions use the shock to limit suspension extension. In this case you will decide how much extension you desire a then measure. Now we can figure your shock length.Max extended length=maxlength 1.5"Max comp. length=oplength - complength - 1.5" You will still need to know the dampning rate of the original shock (tuned to the original suspension) for a starting point when looking for your new shocks. You may not find this information and you may be able to substitute knowledge of the original shock piston and bore diameter for comparison purposes. Internal shock valving can vary drastically! In the end you may need to spend time looking through a shock manufacturers catalog for the correct match.Good Luck