'65 M-21 4-Speed

[DAVE H]

...and, its from a Fremont Chevelle.
Milled 848 case, March 10th assembly date. My research shows this to be a big block only trans with this case #. Appears to be all original external components and assembly bolts. Vin in pics.. Alan Colvins book suggests it to be either a Z16 or a COPO chevelle trans. Can someone please help clarify? The seasoned racer I purchased it from this morning claimed it has been buried in his shop for at least 35 years. The ramrod was a welcomed bonus. Thanks for any and all help. Dave