TCI® has made some design changes in our hardened input shafts for better performance and reliability. We have increased lubrication flow and strength. A resized diameter provides optimum stress distribution along entire length of shaft along with extended high-gear splines to the oil ring. CNC-machined from billet stock, heat-treated and cryogenically stress relieved. TCI® offers input shafts made from aircraft quality Vaccu Melt 300 steel billet, VASCO 300 material and our breakthrough proprietary material found in our new PRO-X™ input shafts. Engines producing over 800 horsepower need VASCO 300 for maximum performance. Engines that have 1200 + hp should be paired with our PRO-X™ input shafts. For 1500+ hp use PRO-X™ ringless input shaft. The Turbo-spline shaft allows installation of a Turbo 350/400 converter in your Powerglide. These shafts require some minor machining of the stator support to accommodate the included turbo support bushing. We also offer input shafts that will allow the use of a 17-spline Powerglide converter with the Turbo-350/400 transmissionPit Stop USAoffers TCI Powerglide Input Shaft 749601 at low everyday prices. Be sure to check out all of our products from TCI Automotive including TCI Automotive Automatic Transmission Input Shafts.