Carli Suspension worked in conjunction with Deaver Leaf Springs to design a leaf spring pack to match our 2.5″ and 4.5″ Suspension Lifts while providing a much more predictable and supple ride with only a slight reduction from a standard 3/4-ton load capacity. The factory leaf spring packs have 2-4 heavy main springs and an immobile lower overload making for a jarring ride; replacing them with our 9-Leaf main pack and 3-Leaf overload provide much more spring rate progression. This makes for a softer unloaded ride, massive suspension travel increase and impressive capacity as the rear end compresses engaging all the springs. The Carli Suspension Super Duty Full Spring Pack is designed and built to our specifications supporting up to 15″ of wheel travel. The center-pin is relocated to accommodate (up to) 38 inch tires, 37″ recommended, and levels the rear perfectly to match our 2.5″ front suspension systems. This spring pack delivers smoother suspension cycling in all situations: highway, off road and towing.