Tcm-glx,
I have the RST 16, Deavers, and RPG drop shackles; and have about 7,000 miles on the set up now...
Droop? Try 22 inches! The extended brake lines are the limiting factor; I put on 18" limiting straps, (with welded brackets of 1" top and bottom for a total of 20") .
Be aware that you do need to cut the passenger front of the bed floor so it mirrors the profile of the drivers' side fuel fill relief. There is a panel supplied with the kit to weld over the cut out. Effectively there is no real loss of bed space.
The upper shock mounts are cut off, as are the lower. New lower shock mount brackets are supplied, and the upper mounts are integrated in the bolt on frame brackets as are the bump stops. There are two cross bars to stabilize/reinforce the bolt on brackets, one of them bolts on to a bracket that gets welded on to a frame cross member.
The Fox 3.5's are amazing. They are also wide! I had repeated problems getting all of the parts for my kit, and had the shocks mounted to the original mounts which were cut off and re welded to the spot the missing brackets were later welded to. In day to day driving I managed to rub the sidewall of the drivers' side tire against one of the adjustment tubes. No damage, but black streaks were left. When the kit lower shock mount brackets arrived we cut off the temporary placed original mounts and welded on the kit brackets slightly to the middle of the axle tube about 1/2 inch. I also put on rear wheel spacers. After some fairly rigorous off roading later, no more rubbing.
The workmanship on the kit is amazing. The customer relations not so. I would highly recommend the kit; just buy it from someone other than RPG.
Eddie