The ICON 2011-2016 Chevy/GMC 2500HD/3500 6-8" Stage 2 Torsion Drop Suspension System was engineered to offer superior ride quality, performance, component protection, and reliability all in one complete package. With over a year of development and testing our suspension system is sure to perform with the best on or off-road handling and drivability. System components and features include a heavy duty boxed sub-frame with integrated differential and transmission skid plates, precision CNC machined cast iron spindle knuckles, adjustable lift height, V.S. 2.5 Series piggyback shocks front & rear, rear lift blocks w/ built in bump stops, and tubular Delta Joint upper control arms. The Stage 2 GM 2500HD/3500 6-8" system upgrades the smooth body shocks to V.S. 2.5 Series piggyback reservoir shocks giving you superior overall performance & handling compared to any other available suspension.; This system features upper control arms with ICON's patent pending Delta Joint. The Delta Joint is a heavy-duty high angle ball joint that combines the durability of a ball joint with the performance characteristics of a traditional uniball. While the industry standard uniball does a great job of allowing the control arms of a vehicle to articulate with little bind, they do have an inherent weakness that leaves more to be desired when used in a daily driven application - exposure to the elements. The Delta Joint features a zinc plated housing providing the first layer of corrosion resistance, while a tough grease seal keeps potentially harmful elements out of the inner workings of the joint. Metal on metal construction and a greaseable design increase the longevity of the Delta Joint while at the same time allowing for noise-free operation. What makes the Delta Joint unique is that it brings the best of both worlds to ICON upper control arms with features that make it more robust than a uniball, and at the same time capable of greater angularity than a typical ball joint.