Fresh 727 Street Strip Trans S.B. Wont Drive

Just so you know, I have seen axles snap off just inside of the bearing.
If you raise it off the ground and wiggle the wheels you can tell if thats what it is.

I could hear the trans shifting, and the speedo worked because the driveline was spinning.
When we put in on the lift I was watching the wheels as it came off the ground and I saw one wheel droop a little.

Yours is probably the splines like the others guys mentioned though.