Could be a muncie like in this link. IF it has 4 bolts on the side cover and shift arms like the link pic.
If it's 7 bolt cover it's a saginaw.
You might need to take us some pics of your linkage on the column and on the tranny, then we can see what you're talking about.
http://67-72chevytrucks.com/vboard/s...d.php?t=621891