StreetGRIP rear lowering coil springs areCNC 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 designallows your muscle carto transition over small road irregularities via a soft spring rate section. When your suspensioncompresses the springs far enough (such as when travelling over large bumps or cornering), the dual rate designtransitions to the firmer spring rate to control the bump or body roll. We work closely with Hyperco, our technology partner, to develop a-body specificspringrates 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, CutlassandSkylark.