Fabtech?s 6" Radius Arm lift kit 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. The design has been proven in over 10 years of service in consumer, commercial and military applications. High quality components with properly designed suspension geometry is what sets this system apart from all other Radius Arm suspensions. Each Fabtech component has been designed with specific features and benefits that create this quality suspension system. For a greater understand of each these components please see below. FEATURES: RADIUS ARM - Tubular construction with dimple die side plate for superior strength. Arms are offset to allow for full turning radius of the Dana Super 60 front axle with wide tires. Fabtech Radius Arms have 1 degree of caster built in for the increased ride height. Adjustable alignment cams on the Arms allow for an additional 1.5-2 degrees of caster adjustment. DIRT LOGIC 4.0 CONVERSION - Simplistic super stout 1/4? thick steel brackets utilize the factory coil bucket to bolt in the big Dirt Logic 4.0 Coilover. A massive 4? diameter stainless steel body with 1.25 NitroSteel? piston rod for maximum corrosion resistance and durability for the most aggressive driving conditions. American made coil springs handle the weight of the F450 or F550 and provide a superior ride. The remote aluminum reservoir dissipates heat for continuous damping when driving over extreme terrain at high speed. The pinnacle of all coilover shocks. TRACK BAR BRACKET - 1/4? thick steel bracketry re-positions the factory track bar to center the axle under the vehicle with the increased lift height. Super stout box style bracket is designed to elimin