[ol_skool_chevy]

It really does not matter what the Trans come out of, In basic terms its a GM 3 speed. They were use in many applications. what's more important is the gears. On the tail shaft are grooves from none to 3 groves. Gearing is as follows. wityh No photos it can be somewhat difficult to ID.

also is there a back up switch?

Saginaw 3-speed 1st 2nd 3rd
No Lines (grooves) 2.85 1.68 1.00
1 Line (groove ) 2.54 1.50 1.00
2 Lines (grooves) 3.11 1.84 1.00
3 Lines (grooves) 3.50 1.89 1.00