I thought that originally Thrivers were meant to have a driver sized heads with 3 wood loft and 3 wood length shaft. I built one using one of the older model Hireko Thriver heads (think it was 16, but might have been 13) , shafted with a Pure Energy shaft. Since I'm pretty accurate , but short, with a driver, usually 11/14, the Thriver did not give me any advantage. It was shorter, with the same accuracy as my driver and quite high in flight which cancelled my ball run-out, it didn't bring anything to the table. Sticking with my Cally GBB 12.5* Kuro Rgae.