It seems that every PC built on an E350 chassis sag a little, some models more than others. Our older less load-capable 2007 E350 chassis has a slight sag as you can see in the picture below. Our rig has no slide out so that reduced weight reduces the sag by some amount. The picture was taken during one of our trips with a normal on-trip load. It's not much of a sag but it's there.
I had considered installing those affordable Firestone air bags where you add air like in a tire to get a few inches of lift. A few inches is all I would need to get the rig perfectly level. I never did get the air bags because I feared the ride would get more harsh, and in my case, the a/c unit might hit the top of our garage door opening if I forget to let the air out when back at home. The softer ride is more important to me than lifting the rear end to get the rig perfectly level.
I really should place our PC on a level parking pad and compare that to the floor inside the rig. It would be interesting to note any differences. I would do it in our garage but the garage floor is sloped to drain water towards the garage door.
