The new PRG spring pack is leaps and bounds ahead of the stock pack as far as performance is concerned. Greg at PRG tells us that the new pack should not sacrifice much load-carrying capacity either. You can see the difference between the stock three-leaf pack, above, with overload spring and the new nine-leaf pack using a double-wrap spring-eye configuration. The new springs combined with shocks allows the rear end to move 11 inches while lifting the rear of the truck 2.5 inches. They bolt on in stock locations; only new U-bolts are required.