Chevy Overdrives appear on eBay quite often. 55 through 65 pickup or passenger will work. 66-68 Saginaw will also work. Its a lot heavier transmission than the Muncie but they are rare. I found one here at a local swap meet a few years ago. The guy hadn't sold anything and he needed gas money to get home. I really don't think he knew what he had. Very few salvage yards have anything 50 years old any more. And fewer have anyone who knows what is what. They all rely on a computer. There are several on eBay right now including a Saginaw that I would grab if I didn't already have one. Just do a search with "Chevy overdrive".
