"You don't have a clue. You couldn't get a clue during the clue mating season in a field full of horny clues if you smeared your body with clue musk and did the clue mating dance."
The leaded valve for the Tial 38mm can handle leaded race gas. The 44mm and 46mm come standard with a lead tolerant valve. I have so far seen 2 Tial 35/38mms sieze up from using leaded gas with the normal valve.