I added the 5000 lb. Supersprings and it made the shocks work better which I had not anticipated. With better load support their was a reduced range of motion and the shocks range of travel was also reduced.
With my 5,000 lb. set there were two leaves for each side of the truck. I removed the inner leaf initially which is simple to do to see how the 4,000 lb. (total support with the factory leaf packs). Performance was good with the single leaf on each side but was definitely better with both leaf springs (4 in total).