I would also confirm Squeeze's comments about a direct replacement. I replaced the the stock 3-speed in my 57 Chevy pickup with an OD 3-speed. It was a direct replacement, driveshaft, mounting, etc. I also have a lower ratio rear, so I am very happy with my setup. The "Burb" link is a good one. In addition I got a "compiled" manual from a contributor to this forum (don't remember who) that was helpful. The factory manual also has info on the OD unit in it. Last, with some digging, I did find some alternatives for wiring it. At the moment I don't know exactly where. Basically if you dig around you can find some good info.
