Kevin, I did a little peeking through the web and found a post on another forum that says the Saginaw 3 speed OD transmission repair and overhaul instructions can be found in the
1961 Chevrolet Passenger Car manual. I don't have one of those books to check, but feel confident that the info is accurate.
There are a bunch of those available on evilbay like
this one that wasn't the cheapest, but the best condition for the least money. Hope the info is helpful.
