Aftermarket upgrade - 315lb spring rate for a soft ride
PLEASE NOTE: this spring is manufactured to mount to the 1963-77 differential rear cover (which can be identified by the four 9/16" bolts which hold the spring in place)
If your Corvette is using 7/16" bolts to mount the spring, the differential cover has been replaced with a 1978-79 cover. If you have a later model differential cover you MUST order the 637017 or 637018 a later model spring