Dana with 3.54 gears, 35-spline Detroit locker.

Nine inch with 3.50 gears, 35-spline Detroit locker.

Same length wheel to wheel.
You don't need to know anything else.
Which is stronger ?

The Dana, by a good margin.

Ok..... on a “Don’t need to know anything else” basis, i see you with two grease covered junk yard rears from old rusty pickups that you paid a c note for. In this case, pick the Dana....

It depends on what parts are in the 9". A good aftermarket one will be stronger. A stocker will not be close.
Doug

Like always the "stock" Dana is stronger than a "stock" 9"
Now build a 9" without ANY Ford parts then the race is on. Three bearings to support the pinion against the ring gear will ALWAYS be better than two
And yes it will cost about twice as much but in the end you will have a better unit.
Still have a Dana in my car though

Gus

Well..........

The Dana is going to be stronger given the critical fact "Detroit locker". Per Dr Diff on another thread some might remember:

"The size of the 9" differential is dictated by the presence of the third "pocket" bearing. Because of this, 9" differential internal parts are much smaller and weaker than the Dana 60 version. This is not a concern with a spool, but it gives the Dana 60 a big advantage for a heavy/torquey street/strip car with a traction differential."

OK
I'll play because I'm having the same delema.

Strange S-60 or Strange 9" complete rear

One other thing WEIGHT?

I heard the S-60 is only 15lbs more

Cost?
This will be going in a 1971 Demon

100% agree

If you want to get into more detail, the Dana 60 is one of the more efficient rear ends, even more than an 8 3/4", while the Ford is one of the worst. It's a small percentage, but it is there.

It has to do with how close the pinion is to the ring gear centerline. Plus, the Ford has an extra bearing - more drag.

If you know the gear you'll be staying with, go Dana 60.

This ...I am currently in the same dilemma, I will probably go with a 9" Ford simply due to the ability to change 3rd members as necessary.

Build one w/ good parts and the 9" is better.

That efficiency argument is a wash. You'll never see it, unless you're in a low powered class car that needs every tiny ounce of free movement to run a number. The benefits of an aftermarket 9" far outweigh any efficiency issue.

Personally if I were to build a new rear-end I would go with an all aftermarket 9" - Cost wise you can build a S-60 cheaper than a 9" but the gear availability of a 9" is better and the ease of the gear change is also much better.

My S60 in the Duster is 198lb with strange calipers/rotors.

The gear swap deal... I have my 4.30 gear on a separate spool so a gear change can actually be done in a timely manner as it has its own shim pack & the S60 has side adjusters so that takes a lot of “grief” away from set up over a D60.

We went with the Dana style as it was a somewhat affordable “set it & forget it” rear for when my dad had the car. From a weight and gear selection standpoint, I think I would have gone with a fabbed 9” based deal. Or 8.75+.25 for you Mopar purists

Yes the 8 4/4 is a popular swap Jay lol.

I went Dana mostly due to cost, and I knew it would be plenty for my car. For the cost of having two good 9" 3rd members ready to go I can have the local diff guy swap gears for me many times.

Lets be honest. A 9" looks improper under a Mopar.

Thank you all for your responses.

If I could corral this back in a little....

Given the same aftermarket axles for each rearend ( shortened ),

Which is stronger ?

Not which is cheaper, which is lighter, which is prettier, etc.

Possibly the comparison comes down to the Detroit Locker itself
in each rearend, or maybe the gear hypoid offset...…????

The D60 will handle over 1000 hp.I remember the article switching from an 8 8.75 t0 a D60 with the dana being 50 lbs heavier with no change in E/T.
I still have the spool that came in the car 30 years ago!

If the 9" has a stock centersection, then the Dana is stronger.
If the 9" has a good aftermarket centersection and pinion support, then it's the better choice.

I can't comment on the differential, b/c everything I have uses spools.

My comment would be... if you’re using a Detroit locker, it doesn’t matter. Street tires wont hurt either one.
If you are planning on using a Detroit locker with slicks, you should change your plans.