Today I delt with a guy on the telephone at this place WA.
http://www.aspirevelotech.com/Merchant2/merchant.mvc
I'm trying to fit a nice alloy headset to the '73 Super Sport Dr.Deltron is painting. They couldn't answer the question about tpi, but said they would call Chris King and get right back to me. When he asked what I was planning, and I told him, he was very interested, asking about paint color, decals, and the other components. It was a great experience.