Hot Rods Identify transmission

Helping a friend liquidate. Can anyone ID this trans? He said it was behind a 364" Buick. Engine and trans were in a T bucket show car many years ago--still has the motor too--low mileage and runs great. Kinda looks like a Hydro to me-trying to get more epics and info--adapter is unknown to us Thank you

 

Yeah, my thought is a GM Hydro with a bell-housing adapter for the nail.

 

There's a tag on the RH side with the info ... unless it's gone. Being floor fill, it may be a single range or Chev - GMC truck.

 

THX--I'll ask him to get numbers

 

.. with a modified Powerglide shifter from a '64-'67 Super Sport, from the looks.