Aluminum reduced suspension system holder the BACK of this rear suspension system. Redesigned to move the inner pivot location nearer to the car center enabling to utilize longer and smaller suspension arm alternatives and new suspension system geometry. The narrower design increases rear traction. The aluminum suspension holders feature built-in Suspension Settings (I.S.S.) which allows for fast & easy suspension geometry set-up. Machined from premium Swiss 7075 T6 aluminum and black colored coated. Utilizing eccentric suspension bushings placed into aluminum suspension system blocks, along with additional suspension system shims, the XB4 suspension system geometry are entirely modified.