Feuling Endurance Beehive Valve Spring Kit For Harley EVO / Twin Cam / Sportster Features Feuling has developed new endurance BeeHive valve springs that are machined from a premium grade Hi-tensile chrome silicon single conical ovate wire They are shot-peened with a specially processed thermal heat treat and super NexTex finish to give these valve springs the needed fatigue life to exceed the high demands of V-Twin engines from stock to performance Kits include: Feuling endurance BeeHive valve springs, lightweight 7 super Titanium heat treated retainers, machined chromoly spring seats and valve locks and a set of premium Viton valve seals equipped with a spring loaded valve stem wiper system. Spring pressures are 185 lb. at .635 lift and 160 lb. at .650 lift 7, 5/16 valve stem and keeper groove