So let me get this straight. Ti valves are not legal for Stock replacements?

I was talking with a stock eliminator racer the week before Indy about some thinks on his car. A few other guys walked up and started talking with him and they were asking what all you are allowed to do to your engine in stock. You will never guess what came out of his mouth. He said that he was allowed to use Ti valves. I quickly said "Do What?" and he's like yeah you are allowed any aftermarket valve. I was like really? Saweeet! I'll get right on that.