The 4" lift for the coil sprung Super Duty is achieved via engine specific coil springs to ensure proper lift height and maintain factory ride quality. Radius arm lowering brackets are used to restore proper caster angle / alignment. Other components included with the 4" system are: front compression travel-stop relocation brackets, track bar relocation bracket, front anti-sway bar extensions, and a steering stabilizer bracket. The kit is packaged complete with Superlift'superide or Superide SS shocks by Bilstein. Options include multiple steering stabilizer choices including dual Superide or Superide SS series stabilizers by Bilstein and a Radius arm to 4-link conversion kit. NOTE: If equipped with a two-piece driveshaft, also order carrier bearing drop bracket part number 9649. NOTE: Most Super Duty trucks have a 1.91" tall factory block and DO NOT have top mounted overload springs. If the vehicle is equipped with a 1.91" factory block and top mounted overload springs OR a 3.71" factory block without top mount overload springs a longer rear u-bolt kit, part number 11664, is required. If the vehicle is equipped with a 3.71" factory block and top mount overload springs a longer rear u-bolt kit, part number 11674, is required.