What type of metal should you use? You could use Titanium! Got cubic inch money? You could use Stainless! Middle of the road! Most Professional Machinists consider Stainless Steel the lowest choice for a valve. Then there is a "Stock" valve! Who knows what they are made of! Feeling Lucky? I was not. My 1972 455 H.O. Formula Motor sucked a stock valve, broke one head, traveled across intake manifold dropped into cylinder on other side and got shoved into that head. DID I MENTION STOCK VALVES?
