I know you're all talking about the Deuce here, but I thought I'd share what I did on my M818 to give some more ideas.
I tapped into the old trailer emergency air hook up. I kept the existing trailer shut-off valve and installed a 1/2" pipe along side my tool/utility box. The 1/2" line terminates with a ball valve and a 1/2" quick disconnect. There is a flexible rubber line between between old trailer shut-off and the new new pipe. The pic of the flexible line is older as I now have lengthened it and installed quick disconnects in the middle of the line to accommodate an air pig. I also carry 3/8" and 1/4" quick disconnect adapters.
This set up is easier to use than the rear emergency glad hand. I use this connection along with an air pig when we changed all ten tires and when I air up the tires.
The set ups between trucks may be different, but I hope this may help you along with your install.