I ordered mono leafs for my 51,3100 from patricks,I don't think he carries them any more,patrick shipped my his new front end kit for my 51. The kit consisted of new front springs four leafs each and new shackles and bushings and lowering blocks and u-bolts for the rear. This set up lowered the truck by about two inches,I'm happy with the look and the improved ride. old navy 51...............