FEULING« BEEHIVE« valve springs use a much smaller and lighter weight retainer which drastically reduces the valve weight creating a much quicker revving and smoother motion than comparable dual valve springs FEULING« endurance springs are a direct bolt-in replacement up to 650 cam lift no machining or rocker box clearancing required Eliminate valve spring separation, maximize stability, reduce valve-train noise & harmonics FEULING« BEEHIVE« valve springs must be installed at the correct open height, matching max lift to the open height spec of the valve springs Kit include: FEULING« ENDURACE BEEHIVE« valve springs, lightweight 7? Titanium heat treated retainers, machined spring seats, seat shims, valve locks and a set of premium Viton« valve seals equipped with a spring loaded valve stem wiper system. VALVE SPRGS ENDRNCE SE