Could a 67 ss come with a Saginaw then?
Yes, but not a Saginaw 4 speed.
If it's purported to be an SS and purported to have come with a manual transmission, it either came with a Muncie 4 speed, a Saginaw 3 speed or a Borg Warner heavy duty 3 speed. Of the three, only the Muncie would have come with the speedometer hole above the throttle lever.
Post a picture of the trim tag.
Ed