BlueBlaze, I have to question whether the air bags are properly installed. I had them on a 2005 Dynamax (E450 Ford, B+) and usually ran 30 pounds which raised the rear 2”. 65 pounds would raise it 4” but roughened the ride. As you add air the rear of the coach should rise. You might want to leave all of the air out, have someone crawl under the coach and watch as air is added to figure out why the height doesn’t change as the bag expands. Mine were a big help to the sagging problem and helped with the handling as long as I didn’t go too high on the pressure.
Does raising the rear end require realignment?
my 2350 measured 32.5" at 40psiBlue Blaze - if your 2008 measured 33.0" at zero psi maybe the previous owner replaced the springs or added a leaf to fix the sag.
If you have leveling jacks maybe check if the suspension will extend any further than 33”-34” with with zero weight on the springs??