T-316 will work, but it's not the best
The best for your application is called Aquamet 22. It's available from Western Branch Metals in Portsmouth Va. There is also a place in the Detroit area, as well as New Orleans, and the west coast. Essco Metals in Calif. & Oregan also carries boat shafting. Western Branch will supply the shaft tappered with the keyway machined. WBM's number is 800-446-8133. If your shaft is just bent, why not take it to a machine shop or fabricator and have it straightened and polished? Much cheaper than a replacement.
