For what it's worth, my 15 yr old son has a 105mph swing speed. I was looking, and found, a wishon 919thi driver on eBay that had what I assumed to be the wrong shaft, an integra 45gm shaft, but planned on getting him fit for a new shaft. He has loved it the way it is. Hitting on trackman last week his drives were incredibly tightly dispersed and distance was 290. Now we are wondering if we really should even mess with changing the shaft out. The best part is it was hardly hit, looks new, and I only paid 65 dollars for it. I would suggest looking for a wishon 919thi. Don't believe all