The shaft that you would ideally want is a "P" shaft. This is the one that is longer and supports the clutch bell. If you have a short shaft engine it's no tragedy. Ofna makes a clutch nut that "adapts" that style with a an extension built into the nut.
"I have no idea what you're talking about, so here's a bunny with a pancake on it's head."
In mind and body, we're all heading towards old age. It is slower to go by bike.