Superlift rear block kits help distribute the weight of your cargo and improve the towing performance of your truck. They'll also give your rear a little lift to bring it back to the proper ride height. The fabricated block kits are designed to take the place of your factory blocks while the cast iron kits work with your existing factory blocks. The taller blocks will increase your rake and they work well with suspension leveling kits. Superlift includes all the necessary mounting hardware and new U-bolts will come with your new rear blocks. It won't take you much time at all to swap these in for your factory blocks. Make towing or hauling with your truck better and safer with Superlift rear block kits, they'll help make your truck "super"