Hi Nomadist,
Our rig is 23'-8" over-all length, just a tad bit longer than your rig. Our weight placement is tail-heavy and front-light. What I did is not a full encompassing solution to your dilemma, but it was an easy and affordable increase in tail height, leveling the rig, and also ride-comfort.
CLICK HERE to read about it which includes some detail in picture fashion. In your case, I would install rear air bags which should increase your rear ground clearance a couple extra inches. Between the two changes, you could increase your rear ground clearance by roughly 3".
If your rig is built on a Ford E350 chassis and suspension improvements were not yet performed, I strongly recommend the following.
- Add a heavy duty rear stabilizer bar. You have no rear stabilizer of any kind.
- Replace your weak front stabilizer bar with a heavy duty version.
- Pending the condition of your shock absorbers, replace them with heavy duty Bilstein shocks.
Those 3 changes will improve control, not increase rear-end clearance.