I am looking at a 74 duster.
The owner said he has put a "Dana 40" in the rear.
Is their such a thing?
Is this a good rear end?

I'm not so sure about a "Dana 40", but I do know there's a Dana 44. Used in both ends of I.H. Scouts from '75-'80, and the rears were all limited slip diffs.

Roger

I know Jeeps had the Dana 35 and 44, and lately have come with the 29 spline 8 1/4"...I know that at a glance it's tough to tell the 8 1/4" and the Dana 35 apart unless you really look at the rear cover, never seen a Dana 41 or 44 under a mopar car...

Dana 60, that becomes a different story there...

-D.Idiot

if it is a dana 44 , is it a good one to get?
I currently have a stock 7-1/4".
Thanks

It seems like the seller is mistaken about exactly what the car has for a rear end.

Take a look at the pattern of the bolts on the differential. There are websites that identify different types of rear ends by the bolt pattern.

Here is one for Dana differentials:
http://www.nationwideparts.com/differentials.htm

There are other sites that show Mopar differentials, etc.

- Mac

If it is a Dana 40 (which no one has heard of) it is so rare as to be useless. Dana 30/35 is no stronger than what you have. Dana 60/70 is way heavy/expensive for your application

If you want to replace the 7.25 look for more common replacements like the 8.25.

Even Dana 44s are rare enough these days that most would take a pass. I have a Dana 44 here....but you wont like the bolt pattern.....or the rotation.

_________________
Yeah....Im the one who destroyed this rare, vintage automobile.....

My '04 Wrangler Rubicon came from the factory with Dana 44's in front and out back. My '97 Wrangler has a Dana 30 front and a Dana 35 rear. In my opinion the Dana 44 is a great axle and is a popular swap upgade with the jeepers-

_________________
83 B150 /6 4spd
97 JeepWrangler Sport 4.0
2001 VW Beetle TDI 5sp
2000 Nissan Xterra
73 Dodge B300 van

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You are correct, for the intended swap/application. We're not claiming the Dana 44 is a bad axle. In a Duster, as an "upgrade" to what some might call an anemic differential, not so good.

The beauty of the Dana 44 is that it came in Fords up front, Scout II's at both ends, and I think Chevy used them in Blazers, along with Dodge in the Ramchargers. The selection of different mounting methods and left or right side short axles for a front diff, make it a great upgrade for Jeeps, and there are still a great many factory and aftermarket parts available for them.

Roger

In 4wd Chevy trucks the Dana 44 is matched to a GM 12 bolt rear. The 44 is the front axle of my GMC 1/2 ton. The 44 has an 8-1/2 inch ring gear.