One thing to consider is the bending of axle tubes. This was always something Monte Smith pointed out. At high power levels, you can't stop the tubes from bending on a Dana. 9" rears have all sorts of stronger housings and their design makes them easy to brace up real good.

The Dana housing in my car is bent and I'm not at a really high power level so it only takes a heavy stick car with a stiff clutch and medium traction to bend one.
There are some guys that brace them with tubes and heims like the 8.8 Ford guys do.

I'm not sure the back brace tubes do any thing with the Ultimate 60 covers have but it looks cool
Gus

Maybe forget all this nonsense and put a Rockwell F106 truck rear in the car
Gus

That looks really expensive...

I don't know how much power it takes to bend Dana tubes? But mine hasn't bent them in 525+ passes at somewhere north of 900hp. 1.25-1.30 60ft@3350lbs (or 3500lbs+ with ballast). The first Motive street gear went 425 passes before it bent a tooth. The 2nd no name street gear only went 100 passes before it broke pinion teeth. This time it got a US gear Pro Gear. I also added the LPW cover like shown above. Braces were not added at this time. We'll go do some real word testing and see what happens,
Doug

OK since I'm chasing light 9" with aluminum center section and gun drilled 40 spline? Do they make gun drilled 35 spline?

Strange charges around $140.00 a pair to drill 35 spline axles when you order them.
Mark Williams will also drill 35 spline axles but I'm not sure what they charge

Gus

I tried to buy the lightweight gun drill axles from Strange for my 1965 Dart S/P car and I ended up letting the female sale clerk talk me out of them
I was planning on ordering the gun drilled lightweight 40 splines at first and she talk me down to the standard 35 spline race axles due to it being a "bracket car"
Never again will I let someone talk me out of better parts especially in the drive train

I think mine may have happened before I got some better shocks on my car. I was racing at the Chrysler classic event about 4 years ago and it hooked hard and unloaded the suspension and bounced the left rear tire off the track. My buddy actually took picture and the car had 3 wheels off the ground. It also bent the wheel studs enough that I had to cut them off to unscrew them from the axles.
Ever since then the axles are hard the get in and out of the housing. They are Moser 35 spline axles and spool installed a 67 factory Mopar housing. It was a violent launch and I'll never put a 5500 chip in the 2 step again.
Gus

I would take a pair of 24 inch long carpenter squares using a helper to measure the toe in and toe out off of the axles flanges out 15 to 18 inches in front and back to see if the housing is bent or not
Better to find it now and stop the damage before it hurts you and the car

I put the car up on the alignment rack at work and the rear alignment was pretty straight. Very slight difference between right and left.Not enough to be in the red anyway but it wouldn't take much to make the axles bind up in the splines. I recently installed a PowerLock unit with brand new upgraded spider gears and it was even worse with brand new splines.
There is a rear end shop about 40 minutes away that can straighten my housing and re-tube it with chrome molly tubes if necessary.
This is the deal that the Mustang guys are running
Gus

she musta had a pretty voice...……...

I think she had a valid point for you Cab...

I noted last spring checking some stuff out that it was more difficult removing my right axle. Really not bad enough to worry about it, but noted. Possibly one of the times ladder mounts were welded on? I hardly think I’m making enough power to do it.

I have the gun drilled lightweight 35 spine axles from moser engineering in my S-60 - This rear-end was in a FAST car for about 20 passes and was replaced with an 8-3/4 for weight saving - it also has a lightweight spool and the big Ford bearing on the axles - all for weight savings

the dana 60 is faster and stronger than a 9 in. the popularity of a 9 is being able to change center sections faster. the popularity is why gear companys have more ratio selections. you all have to remember it is not horsepower that breaks driveline parts, its all about car weight. a 500 hp car at 4000 pounds will break more driveline parts than a pro stock car will. if pure strength is all you are after and are not going to change ratios dana 60 all day long my car has had the same gear in it since 1999 when the car was built and that is using a trans brake too. it will 60 ft 1.33 at 3360 pounds

This is all true.

I agree but still run a Dana 60. Most of my buddies all have there cars dialed in with 9", so the simplicity of being able to do a quick gear change never matters anyway. They have been running the same gear ratio for years now. The major benefit beside new parts availability is to build a spare center section & to have in the trailer if you break one.

This is a good and informative post. I don't mind rehashing this stuff once in a while as it clears out the cobwebs.

My only [censored] about the S-60 in my red car is that they didn't box the spring perches.

If I had a decent fab shop that could make a housing locally I'd have gone 9". The dana was easier because I could order it and know it will fit based on what was in the car. We were very hesitant to send a pile of money and a build sheet several states away and hope everything fit when it showed up.

What can I say my dealings with Lenco made me very gun shy when it comes to ordering custom big dollar (for this household) items from afar. 90% of my dealings with the "big names" in high performance were rather disappointing.

That said the 10% that lived up to their reputations kept me in the chase for a fast manual trans street car. They all recognized and rewarded hard work.

If my big tire car (the black '66) ever needs any major rear overhaul it will get a 9" with a spool as it is a plated strip car.

The 9" when done with good aftermarket parts is obiviously the cream of the crop. However for 95% of us here the Dana 60 is a cheaper option. We aren't changing ratios at the track. Though if you set up a 2nd set of gears it would be about as quick. And WAY WAY cheaper. In fact most here can probably get good service life from an 8 3/4. Dollars are hard to come by. Spend them wisely.
Doug

A 9 in rear was NEVER put behind a diesel engine in a truck. A 9in housing is lighter then a dana 60 ... so it comes down to what it will be used for.