The flange on the hedmans is 3/8" with a washer and 1" bolt, I am bottoming out on the EZ heads. I still have my TTI's wrapped up, but am sure that they too have a 3/8" flange. How thick of a washer are you using? It seems that the 3/4" bolts are too short, even wo a washer. Maybe I can grind down the 1" bolts?