These input shafts are availalbe in two different materials to accomodate your specific needs and budget.  The first is made from "true" 300M with a 315,000 PSI tensil strength.  The second is made from an undisclosed material that has a 394,000 PSI transile strength.  Both of these materials start out being x-rayed & certified to ensure quality throughout.  From there they go through the machineing process that is closely overseen & inspected so that every input is vertually indentical.  Both of these inputs have been put to the test & provide run afterrun realiability.  Theya re both also "ring" style so they are a direct replacement which enables them to be used with the original cooler circuit, which has proved to be very important for realiability & durability.

 *Both of these inputs are products of Hutchs Racing Transmissions (London Ontario, Canada)