If you are talking about a manual transmission counter shaft, I have a few in my tool box that I fabricated out of wood. I have found that if you look around, you will find a close enough diameter wood handle on some broom or tool that can be cut down to length. Hope that helps
you can use an old countershaft for OD trans as it will slide right through , for regular 833s the diameter has to be a few thou smaller to slide in , Mopar sells or sold the tool through Miller tools which is what I have , I have heard of using wood dowels , garden hose or heater hose too