Ridetech 11334799 63-72 CHEVY C10 4IN LOWERING REAR COIL SPRINGS SOLD AS PAIRRidetech 11334799 63 72 CHEVY C10 4IN LOWERING REAR COIL SPRINGS SOLD AS PAIR Add StreetGRIP rear dual rate springs to yRidetechs 1963 1972 C10. The dual rate design provides the best of both worlds. The soft spring rate section helps yRidetechs truck to comfortably transition over small road irregularities. As the springs compress further (through large bumps or cornering), they transition to the firmer spring rate to better support the greater