An integral part of the 3.5 Inch system are the new Radius Arm Drop Down Brackets that are designed to reposition the factory radius arms in the stock position in order to retain correct OEM suspension geometry. When you increase the suspension lift to 3.5 Inch, the radius arm angle changes which in turn causes a conflict in spring position as well as axle positioning. The radius arm brackets are a necessary ingredient to achieving the increase in lift while not only maintaining the factory geometry, but also the Factory Ride. Brackets are made from strong steel and utilize the existing radius arm frame pockets. The 1 Inch lower spring spacers are constructed from 6061-T6 billet aluminum and mount between the axle pad and the bottom of the coil spring. This kit is designed specifically to work with trucks that have a upper coil spring spacer.