What tranny is this?

[Southtowns27]

I came across this tranny and I'm not exactly sure what it is, but I know someone on here knows. It's a 3 speed that came out of a '64 Impala with a 283. The unique thing is that it has an overdrive on the back of it. There is a cable activated lever on the OD as well as an electrical solenoid of sorts. If someone could tell me what this is/how it works/where to find out how it works, that would be great. Thanks in advance

[oldskydog]

Sounds like the factory overdrive used since 55. They are neat when they work. Do you have the cable control under the dash and the kick-down switch on the carb? I have one and i'm thinking I might use it on my 55 or 56. Any factory service manual from 55 to 64 should have a section for the overdrive transmission. The assembly manuals have the installation drawings showing all the components.