You've got a couple working against you here.

1. There's a tremendous difference between the empty and GVW.

2. The huge unsprung weight of that heavy rear axle with the duals.

When you get the truck finished and the camper fitted, you might want to consider "de-rating" the suspension down to the new weight of the truck. Since the weight of the truck won't vary as widely as it would when it was a beast of burden you can tune the suspension for a much better ride. You might be able to swap springs from another model or another make of truck.

Compare the weight of the super singles to the duals. Any weight reduction will help out.

I've always thought these trucks were pretty cool. I've considered buying one to outfit as a tow vehicle with a sleeper cab. Kind of like a mini semi for towing 5th wheel campers.

Need some pictures!

__________________
-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250