Minimize wheelhop and enhance the rear stability of your S550 or S650 Mustang by decreasing differential movement with polyurethane differential bushings from BMR Suspension. Polyurethane is a synthetic polymer with many properties that make it far superior to OEM rubber for bushings. Polyurethane deflects far less that soft rubber, and it doesn't breakdown from exposure to petroleum products, road salt, ozone, and other elements of the harsh undercar environment suspension bushings live in. BMR Suspension's polyurethane Differential Bushings (BK049) drastically decreases differential movement and pinion rise over the factory rubber bushings. BMR designed its polyurethane differential bushings from 95-durometer polyurethane. This material offers huge reductions in deflection without excessive increases in NVH. Each bushing is manufactured to strict tolerances, using exact molds, which are designed by BMR. This allows for a perfect fit and increased performance for any driving style. If you have stock power or huge power, and plan on launching your car hard, BMR includes heavy-duty hardware for the Polyurethane Differential Bushing Kit. A small percentage of customers have experienced differential mounting bolt failures with various differential-mounting solutions, including OEM bushings. This primarily occurs with higher than stock power levels, or with hard launches on the street or track. BMR's heavy-duty hardware helps combat these failures. This hardware is not necessary for all customers, but BMR supplies the upgrade for those who have higher than factory power levels or plan on launching their S550 or S650 hard on the street or at the dragstrip. This hardware upgrade requires slight modification to the rear differential mounts. BMR Suspension's BK049 Differential Busing Kit is available in red with zinc-coated hardware. Installation time is about 3-4 hours and may vary depending on stock bushing removal technique. Proudly made in the U.S.A.!