I have 19.5s on my 2017 5500, so my air pressure numbers are a little different. Truck weighs 12.2K Lbs with 112 gal fuel, me, my wife, and dog. I dont change pressures loaded and unloaded. 95lbs front; 90 lbs rears. between 90% to 95% to towing heavy duty cycle.
When I get back on my feet from surgery, gonna rotate tires, side to side, and install my Centramatics front and rear from my 09 4500. They really work great.
Vivian and I put 15K miles on this truck and 65K miles on our 09 4500 RV across the country and into Canada. Some say the 4500/ 5500 ride rough, but we're fine. My friend has 2018 Max Tow Ram 3500 with air ride, and ours rides about an 8 out of ten and his rides 9 out of 10. A lot of the ride IMHO is air pressure of the tires. Plus, 14 ply rated 19.5s have much more rigid sidewalls.
Happy Trails, Ron