These steel valves offer increased durability and easily extends the lifespan to three times that of the O.E.M. titanium valves. Nitrided valves offer high microhardness while a super-smooth surface finish reduces friction between stem and guide. Special stronger valve springs deal with the extra weight of the steel valves. Fully rebuildable with O.E.M. retainers, bases and seals without the need of any further engine modifications. Intake and exhaust kits complete packages for quick, easy and cost efficient replacement. An alternative where the O.E.M. application uses expensive and less durable titanium valves. Springs are made from premium chrome vanadium steel for higher performance and durability under high RPM.