Supertech valves are the best on the market, made from one piece of forged stainless steel for the ultimate in strength and durability. Supertech valves go through a special heat treatment process that obtains the right amount of harness for each engine to ensure the ultimate valve for your performance motor. Supertech offers their valves in either chrome coating, used in high performance valves, or hardened black nitrided which is most popular in European and Japanese motors.