Art,
Are you talking the air pin or an air hitch??
IF you have the Trailair pin, just a thought, have you looked at the shocks on your tow yet??
We had the Isolator installed (similar to the trailair pin, engineered by the same men), and on the way home we were still bottoming out. It was a jarring experience, and we could actually hear metal smacking metal.
Took the OEM pieces of crud, err, shocks, off and replaced with the "B" (see the sig line), and the difference was VERY noticable. Solo and towing it made all the difference in the world.
18,000 miles and the OEM shocks were trash, would not recover, so we were bottoming out.
Your comment that you are getting hard ride solo and with the Montana hitched, is what caught my attention.
Now, for that chucking or porpoising, well, even our air pins won't totally stop that.
That said, Trailair is working on, has in a test market right now, a pin that will address both situations.
Good luck with finding a solution that works for you.