Made from premium stress-relieved conical ovate wire with nitrided surface heat treatment, shot-peened surface enhancements and Nano Peen polish Feature extremely high level of fatigue life Use a much smaller and lighter weight retainer to reduce valve weight and create quicker rev and smoother motion Designed to handle the highest demands of performance engines with high lift, steep ramped camshafts Allow up to 750in lift cams; no rocker box clearancing required Available for 5/16in and 7mm valves Kits include: High-Load BeeHive valve springs, lightweight 10 degree Titanium retainers manufactured from Ti-17 alloy and micropolished for enhanced fatigue life, machined heat treated chromoly spring seats, seat shims and valve locks and a set of premium Viton valve seals equipped with spring loaded valve stem wiper system Spring pressures are 200 lb. at 1.850in (.635in lift), 185 lb. at 1.900in (.685in lift), 415 lb. at 1.215in and coil bind at 1.125in Dyno proven and track tested Made in the USA Feuling Beehive valve spring kits are direct replacement with no machining or rocker box clearance required up to .574in lift for 84-04 Big Twin and 86-03 XL and up to .700in lift for 05-11 Twin Cam. Larger camshafts require valve guide machining for seal to retainer clearance