I don't know about the Kadee no.820.On my Bachmann 2-4-2t I used the Kadee no.779,they can be mounted at what ever highth you need.I use 5'dia.curve track and have no problems with the couplers.The 779s really look good on the loco too.just my 2 cents,David
Get the Garden Railways newsletter delivered to your inbox twice a month