Supertech Valve Spring KitsnSuper reliable valve spring kits – highest quality, and always the best price!Supertech performance valve springs aremade with premium Superclean Chrome Silicon Vanadium Steel Alloy for higher performance and durability. Computer designed to ensure that wire stress levels do not overpass the limits for long durability under extreme conditions and harmonics are well under control.Supertech Retainers are manufactured with high quality military certified Titanium alloy, CNC machined for a tight fit that will ensure a long durability.