This kit contains High-Quality OEM spec performance replacement parts for 1955, 1956, and 1957 Chevrolet Full Size Vehicles. This complete Polyurethane suspension kit is pre-assembled in the USA and includes the following high performance parts: 4 Polyurethane Upper Control Arm Bushings and 4 Polyurethane Lower Control Arm Bushings. Polyurethane manufactures professional high-quality polyurethane suspension replacement parts for those who want and demand the most solid and dependable performance out of their vehicles driving ability. For more positive control over stability while cornering this is the way the pros go!