The IH dealer should be able to call you back with the right information if you gave them the VIN. If not, the Wisconsin Historical Society has the old line set tickets by VIN, and I think they have them for the mediums as well. They will be able to provide a build sheet for about 20 bucks. They're on microfilm, so it costs money to print them out. The type of transmission will be on that line set ticket. I don't know what type they used on the loadstars in those days, but I was thinking a T436, which would have a direct 5th gear and a deep granny gear.
Charter Member, Old Hippie IH Club
Old fashioned binder freak