I figured my wife (since she normally drives the truck) would prefer to have it removable. I did size it so it fits our single jerry can, or most of the stuff I carry for cutting wood.
As far as a stop goes. I had welded on an additional nut (with the threads drilled out) that lined up with the upper nut and secured the carrier in the "open" position with a little pin. However, I had messed up the alignment somehow and it was too tight against the tailgate. I will probably add that in the future. For now, the carrier hits the welded nut on top and keeps it from hitting the body.
Thanks for the comments guys! :victory: