The only axle that came in the rear of our trucks is a Dana 70U. And also according to Dana there is no such thing as a 71. They list out the 61 front but nothing in the application guide (a list made by them showing what vehicles all there models went in) shows a 71 model

You can check the BOM number on the axle tube. It tells you exactly what you have, when, what options, and what application it went in.This link tells you how to find the BOM and overhaul your axle http://www2.dana.com/pdf/5312-9.PDF.
If it doesn't come through, the link is to the Dana web page/ lautomotive applications/ literature/light axles/Dana70 axles.

 

according to dana that was a special applacation and made 19 years ago for only 1 gear set 3.07.
there's no sense in fighting over it but the do exit and DID come in the dodges!

 

The DANA 71 @the 70U ARE NOT THE SAME!70U is different offset.On a better note,I phoned Randy's this morning and I can slap a power trax lock right inside my open carrier.SWEET!Now for a 4 spd auto so it's not crawling down the highway..

 

I would go with what Randy's said!

 

I don't know if it will help you or not, but I installed a Powertrax Lock-Right in my 92 W350. I really like it. It is pretty beefy (weighs 14lbs!) and was easy to install. You do have to remove the carrier though (it's heavy).

Just follow the directions, put everything together (shims, etc) the way it came out, and make sure you check your backlash and gear pattern when you're done. I installed new gears when I put mine in, so I had to set everything up anyways.

On the street you will definitely know it's in there. They are loud, people will stare at you in parking lots when you are turning, and sometimes you'll get some chirping and grabbing of the inside tire while turning, it's all normal.

I've installed a Lock-Right in this truck, one older Chevy, two newer daily driver chevys, and one in my Jeep. They all worked very well and you will love not having a one wheel peeler any more.