Despite having only 47,000 miles, the valves in my 216 needed replacement due to severe wear. I ordered new valves from Chevs of the 40's. The new exhaust valves look like forged steel, but the intake valves appear to be made of ordinary gray cast iron, a step down from the forged stainless valves the engine originally had, which did not even last very long. Even the stem lock grooves are cast in and not machined. Is cast iron suitable for valves? I wouldn't think so, because it is very brittle and not even especially hard.
