Fabtech?s 6? Radius Arm system for the Ford F450 and F550 Super Duty is built to handle the on and offroad demands of the truck enthusiast. This vehicle?s suspension is more robust than the Ford F250 and F350 and therefore demands specialty parts only available from Fabtech. This Radius Arm system is a complete upgrade to the factory suspension and will provide additional strength for use with oversized tires. High quality components with properly designed suspension geometry is what sets this system apart from all other Radius Arm suspensions. The Radius Arms use tubular construction with dimple die side plate for superior strength. American made coil springs have been designed for a very compliant ride quality both on and offroad. 1/4? thick steel bracketry repositions the factory track bar to center the axle under the vehicle with the increased lift height. The Dropped Pitman Arm uses forged steel construction with high strength material that exceeds the factory specifications. 1/4" thick steel drop brackets reposition the front sway bar for the increased ride height. This allows the sway bar link ends to fully cycle without binding throughout the extended travel range. Brake Line Brackets reposition the factory brake lines down on the frame for the new travel range without having to open the brake system. Keeps factory fluid system intact. Steering Stabilizer Brackets retain the factory F450 or F550 long travel steering stabilizer with a 1/4" thick steel bracket and support brace to help reduce tire shimmy. Steel rear lift blocks replaces the factory blocks for additional lift without changing the ride quality or load carrying capacity. American made U-Bolts designed to attach the entire rear differential to the vehicle. These extended length monotube Stealth shocks have a Nitrocarb piston rod for corrosion resistance and resist rock chipping. Great highway ride with good offroad damping capacity.