30 spline mainshaft ID help?? what is this?

[ritterdavid]

found a decent 30 spline manual transmission mainshaft with some Mopar transmission parts, it measures just over 27 inches and I have never seen one quite like it, any idea what the heck it is for?

 

[Dan Brewer]

Looks like a 727 mainshaft.

 

[Hyper_pak]

OD 4 speed main shaft?

 

[Tech857]

Auto 727 main shaft.