next after Upper Stableloads? Jittery ride on rough pavement

If you look at your upper overload spring, it is progressive. One side of the spring will contact the bumper pad before the other. As a test, remove the StableLoads on the side where the spring touches them first and put your stock pads back in place. This will reduce the preload on the upper spring and make the ride more compliant. The ride will be softer, but you need to make sure the truck still sits level with only half of the preload applied.