I want to use a modern rear leaf setup and keep my original Dana axle. The new suspension is set up for a 3" axle tube, my Dana is a 2.5" tube. Suggestions?

 

A spring is a spring-modern or older, the basic design hasn't changed much.

They are tensioned to carry a given amount of weight. The 53 rear springs were fine as is unless yo have somethng specific in mind.

I might be tempted to drive the truck to the local spring shop and tell the folks there what it is you are looking for (better handling, more support, softer ride, etc) and let them recommend something.

 

What is different about a "modern" leaf spring set up? Like Julie says, a leaf spring is a leaf spring, there isn't much you can do different with them.

 

As mentioned above the springs don't make a difference, the difference would be your U-bolts, spring perches (which should be welded to the axle), and spring plates.

 

When I say modern.... smoother ride, ease in lowering the truck, etc. TCI makes a great kit for the truck, but I've got to find a way to make it work with the Dana axle. Has anyone ever seen or made an "adapter" like that? I could bend 1/4" steel to fit and bring the tube to 3", but I'd rather buy something that's ready to weld.

 

It sounds like you just need different U-bolts and either reuse your original mount plate, or modify the holes in your new one. It shouldn't be a big deal or be necessary to do a bunch of welding or modification.

 

Like Julie suggested take your truck to a local spring shop and tell them how you want the truck to sit and/or how you plan to drive it and have them make you a set of new springs or order a set of replacement lowering rear springs from Mid Fifty, Super sliders (would be my first choice) or Dual Flex from Posies or a set from Eaton.