4 speed vs 727 output shaft

[GoMangoBoys]

I am gathering info to buy all the rebuild parts for the 4 speed OD transmission that I bought for our Challenger.  My son says he counted 30 teeth on the 4 speed output shaft but the yoke that is on our driveshaft has a key (one wide spline). 
The driveshaft and yoke were in the trunk, so I don't even know for sure if it is for our car.
Any insight would be appreciated.
Thanks

[Chryco Psycho]

The spline is the same between the 727 & 4 spd as is the length so the same driveshaft will fit either , the missing spline allows lubrication through .
the exception is the smaller 904/999 small block auto trans with a smaller slip yolk & length