Feuling Endurance Valve Spring kits

FEULING ENDURANCE BEEHIVE valve springs are a direct bolt in replacement up to 650 lift (Twin cam/Evo/XL) and 565 lift (M8) camshafts no spring seat machining required. Machined from a premium grade Hi-tensile chrome silicon single conical ovate wire, 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. 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, no machining or rocker box clearancing required. Eliminate valve spring separation, maximize stability, reduce valve-train noise & harmonics! Available for 5/16", 6mm and 7mm valves FEULING BEEHIVE valve springs must be installed at the correct OPEN HEIGHT, mat