I'm looking into getting a 93 W250 but I really need a 350. What does it take to put on duals? Do I need to add a spring or will air bags do the trick? I'm going to put on a flatbed so no worrys about the fenders. Thanks guys.

 

If all you need is the load capacity of the extra tires, then that's all you need. Add 3" brake shoes if it doesn't already have them and you have a 1 ton. It may or may not have the heavy springs, depends on how it was ordered. Count the leaves, the big pack was 10 leaf. Base was 7 leaf, 1 tons could get an 1800 lb overload leaf on top of that.