Having air systems on my C and my pickup with a heavy gooseneck I have learned that it depends on how much weight is on the vehicle. On my pickup I start with no pressure, load the trailer then using a level return the bed to level position. When not hauling
weight i just keep 10 lbs in the bags. Always keep at least 5 pounds in the bags. The C I have been experimenting and 35 pounds
seems to be a smooth ride, as mentioned too much air and it gets bouncy or rough. Hauling a heavy trailer I put 60 in my C and that was good. If your trailer causes the tail end to drop just bring it up level, try that.