Rear swap?

[Rellit]

Hello community.
I have an 85 D250. 5.9. It has a service body full of tools. I am reaching my 3/4 ton limit. I want to carry a slide in camper. This will put me overweight. I want to swap my diff out for a dual rear. Which, if any,other generation rears will bolt in? I don't believe 2nd generation will work. But what about early 70's?
Thanks in advance.

 

[PaPitt]

MAN I sure want to see the reports on this thread.
I Have a 1988 gas 3/4 ton or D250 single wheel with a Western Hauler bed on it.
& I have a 1989 Dodge D250 3/4 single cab .. That I plan to put a 1951 Ford CAB & FRONT FENDERS onto . & then .
& Then I have a 1978 Dodge D350 dually 4 door pickup. & I want to know if that Dually rear axle will fit in either of my D250 TRUCKS . . I BELIEVE BOTH the 88 & 89 will be the same .

.... BUT I want to know what it'd take to swap that rear axle into my truck.
Maybe my 2nd question will help with HIS 1st question.
Thanks

 

[u2slow]

The dually diffs will bolt right in, even 2ndgen if you cobble the shock mounts and shorten the driveshaft. Two different widths; pickup vs cab & chassis.

The dually tires may not clear the service body.

How heavy are you actually going? The single axles are de-rated to about 6080# and the dually is 7500#. You'll likely exceed your 8510# gvwr first and no axle swap corrects that.

Edit: I realize the 6080# is a dana 70 srw spec from my '93 w250 and an '85 gasser is probably the 60 with a lesser #.

 

[PaPitt]

Do you know the difference in widths of the Dually & the Cab & Chassis.

 

[u2slow]

About 4-5".

 

[Rellit]

The dually diffs will bolt right in, even 2ndgen if you cobble the shock mounts and shorten the driveshaft. Two different widths; pickup vs cab & chassis.

The dually tires may not clear the service body.

How heavy are you actually going? The single axles are de-rated to about 6080# and the dually is 7500#. You'll likely exceed your 8510# gvwr first and no axle swap corrects that.

Edit: I realize the 6080# is a dana 70 srw spec from my '93 w250 and an '85 gasser is probably the 60 with a lesser #.

I'm probably close to 3/4 ton now with the body and tools. I have a slide in camper that will put it over. So I'm sure the dual rear will be fine. As for wheel clearance, I'll cut whatever I have to to get it clear. Or, I can space the body up if need be.
Thanks for your reply!