StreetGRIP rear lowering coil springs are CNC cold-wound from high tensile premium steel by then powder-coated for long-lasting, consistent operation. They improve the ride quality, handling and stance of your A-body. The dual-rate design allows your muscle car to transition over small road irregularities via a soft spring rate section. When your suspension compresses the springs far enough (such as when travelling over large bumps or cornering), the dual rate design transitions to the firmer spring rate to control the bump or body roll. We work closely with Hyperco, our technology partner, to develop a-body specific spring rates to ensure the best possible posiible performance and comfort. These springs fit all 1968-1972 GM A-body cars including Chevelle, Malibu, GTO, 442, Lemans, Tempest, El Camino, Cutlass and Skylark.