I have a muncie 4 speed but have no idea what it's out of. Any help?

These are some of the codes. It has a ten spline output shaft with a ring around it. There are numbers stamped on the main case that read POT17B and 2OP215752.
The main casting body reads #3925661 and on the side cover there is a tag that reads 478218DP.

http://www.5speeds.com/muncie2.htm

Is this a chevy Muncie? and what does the tag # on the side coner stand for?

I'm thinking a '70 Pontiac assembled in Pontiac, MI since the VIN starts with a '2' (That would be 2 (zero)P (Pontiac MI assembly plant) and sequence number.