As you will see in this thread
the owner wanted information about air bags.
When I own Fords the chassis could not support the coach and I had to do something to correct the ride and driving ability.
A 98 Ford I went to a good reliable spring company in the area and they balance the coach ride and raised the frame 3" all around.
The second Ford I installed AIR-LIFE bag system which did the same thing but I had more control of ride and weight distribution.
The air bags systems now have automatic leveling where I had a control on dash to increase or decrease air pressure of bags.
Both jobs cost about the same only my labor was involved with the bags.
You need some thing because your rear springs may also near their limits.
This is nothing new its happened to other chassis's also.