This is all you need to know:
http://www.bachmanntrains.com/home-usa/board/index.php/topic,2359.msg20529.html
Quote from: Len on August 26, 2007, 01:10:23 PM
Whichever knuckle coupler you choose, if you're going to use the original coupler pocket you'll need some Kadee #212 Talgo adapters.
The fill in the space between the small pin in the original coupler pocket and the large hole in the knuckle coupler.
Len
http://www.bachmanntrains.com/home-usa/board/index.php/topic,2359.msg20529.html