Allison 1000/2000/2400 Billet 9310 Vacumelt Steel Input Shaft Made for Performance GM Diesel Allison Applications 50% stronger than OEM!!! TCS Duramax Allison Input Shaft Built to withstand everything thrown at it. Made from a select grade of super strength steel. Shaft is 50% stronger than the O.E.M. shaft. Made from 9310 Vacumelt steel. Precision ground for high dimensional accuracy. Ideal for heavy duty service applications. Input shaft is machined with larger than O.E.M. radius at turbine spline for added strength. This Heavy Duty Allison Input Shaft and is one we sell everyday to Diesel Performance Shops!