Replace the rubber factory rear end housing bushings with a polyurethane setup from UMI. Over time, rubber bushings dry rot, crack and harden, decreasing your ride quality and vehicle performance. The polyurethane bushing kit replaces the two upper rear end differential bushings located in the “ears” of the rear end. Polyurethane works excellent for street and drag racing applications. Note: Must reuse the existing outer metal shell. Installation 2-4 hours.