This is a part that every racer should carry a spare as they do need to be replaced from time to time. The only length available is 4.025" which is standard for the current C or D series PSI blower. Be sure to measure the quill shaft or know what model blower you have when ordering.
Rifle drilling the quill shaft almost removes a 1/4" pound and the bore is then finish honed to remove any stress risers and the bore has a smooth mirror finish to offer the most in strength and durability in this application. Quill shaft is .875" diameter in the center.