What is the best way to get an overdrive auto in a 67 Barracuda?

Which one are you guys running?
Any with Manual Shift Reverse Valve Body?

Part # 3DFS727A Automatic 3-Speed 727 18″ Tailhousing
Part # 3DFS731A Automatic 3-Speed 727 8″ Gas Tailhousing
Part # 3DFS732A Automatic 3-Speed 727 Shorty