Additional NotesThey have been designed to be the strongest and lightest valves available for the Austin Healey. Designed for competition use but we also highly recommend using these valves if you have converted the cylinder head to unleaded valve seats. They have been manufactured from a one-piece electrically upset 214N austenitic Stainless steel forging with a stellite 12 valve tip and a pulsed plasma nitride treatment on the valve.