I thought it would be informative to have a discussion looking at the various aspects of these rear differentials for a drag car. I figure it basically comes down to weight and cost. Can a CM, back-braced 9" housing with 35 spline axles and your choice of carrier (spool, power lock, etc.) be bought at a comparable cost as, for example, a Strange S60?

I am getting ready to put a new rear under my Charger and was pretty set on a Dana 60 for simplicity's sake until a thread recently made me consider a 9". I am pretty confident that a spruced up 35 spline power lock in a S60 can live in a moderately heavy (say 3400-3600 lb car) around the 10.0-ish 1/4 mile ET.

Do any of you guys running 9" rears in door cars care to chime in? How about those heavy E and B body cars running into the high 9's with a Dana? Are you running a spool? What kind of axles? Any info you have to contribute would be greatly appreciated.

For laughs let's say the high side of the budget sans brakes is $3K.

I have about $1500 into my 9" with good parts and
axles(there are some bigger dollar parts over what
I have in mine) but I bought the housing cheap and
shortened it and back braced it myself.. I didnt go
with a spool but spent more on a posi style unit but
a decent one.. thats new gears and bearing through out

That is not bad Mr P. I have had about the same or a little less into the Dana 60's we have built from truck housings depending on the axles, cover, etc. I love the look of a Dana 60 under a vintage Mopar but just had to ask afters searching and reading some of the old threads on 9" vs 8.75. Did you use a CM housing and back brace?

My car has a fuel cell so no problem there. I am thinking a CM .250 tube Currie housing with an aluminum center section and bearing retainer would be cool. The only thing I'd have to change would be my beloved 10" rear drum brakes.

Yeah...I don;t really need the drums for launch on the stick car. I have valve float for that.

---

I have a 5000 stall 8" conv but I'm hoping I can get
3000-3500 rpm at the line... on my P-Body I couldnt
foot brake it at all.. if I went above about 2200 rpms
it would push through the lights and just spin.. it
wouldnt plant the tires.. hoping the Rampage will
plant them with 3000 rpm on the ladder bars

Depends on your application.

I like S-60 rears for high torque, leaf spring equipped street/strip cars.

9" traction differentials are not particularly strong because clearance issues with the pocket bearing at the end of the pinion dictates small moving parts inside the carrier. In contrast, Dana 60 traction differentials are much more robust.

Due to the sheet-metal construction, 9" rears require a back brace for housing strength. This does not jive cleanly with leaf spring perches and shocks.

Because the tubes insert several inches into a machined casting, a back brace is not as critical on an S-60 housing.

The best thing is, I sell a new BOLT-IN, 35 spline S-60 rear with heavy duty S-Trac differential for $2175

Dana 60, 4:10's, 4 pinion suregrip(?), Moser 35 spline axles. It's been in since 2001 behind a 440, 528, 572 and next a 655.
HTH's

We run a none back braced 9 inch 35 spline with a spool in our 3400lb Charger running 9.6X's leaving at 4600 with a trans brake with a 31x14 tire.
Currently the car is going to modifications to run faster so we did jump up to 40 spline and a back brace.

Monte covered this in the other thread:

ANYTHING.......CAN be broken, that is a fact. But it is also a fact that a 9" can be built into a MUCH stronger drop out style rear than an 8.75, as witnessed by the fact being that is the rear of choice under 99% of high HP race cars on the planet. The fact that ANY of those parts may or may not be an original Ford part is a moot point. It is a Ford design.....it's a 9" Ford.

The reason a DANA holds up better than an 8.75 is just because of the massive size and strength of the center section itself. The case will not flex near as much in the pinion area, even without the support bearing of the 9".

While the center strength of the DANA is a plus, its rear load design is a weakness. It is IMPOSSIBLE to properly brace the housing itself, to keep IT from flexing and bending the axle tubes. If the tubes have any length to them, they WILL bend and you can't stop it.

Any of this has ZERO to do with if you are a TRUE Mopar guy or not, it has to do with putting the proper part under your car to do what YOU need to do and it last.

Radials are HARD on parts. The tire is hooked or its not. There is no in between. You CAN'T spin or slip a radial and it still go down like a slick. A Radial DEAD HOOKS and THAT is hard on parts with a lot of power. You will bend or break EVERYTHING in the drive line if it is not beefy enough.

In our own radial car, that weighed about 2900lbs, we had a VERY well built Moser mild steel housing, that was heavily braced. The car was 60 footing in the high teens to low 20 at that time. We bent the housing 3 times. When the car got hard to push, we knew the tubes were bent. It would bend them out at the ends. Have seen it bent as much as an inch per side. Once you got the axles out, they did NOT go back in. We now have a chromoly housing, with .250 wall chromoly tubes and it is braced and built like you would a housing in a Pro-Mod. The car now goes 1.0 60fts at 2700lbs and we have NOT bent that housing. We have 40 spline gun drilled axles, a pro series spool, pro gears and both a Mark Williams or a Strange thru bolt case, depending on what gear we run. Expensive parts......yes..........but we have NEVER broken a gear or anything rear end related.

NOW........does EVERYBODY need the parts we have, of course not. What YOU need, depends on what you plan to do. My issue is with the constant "put a Dana under it" chatter every time this subject comes up. While a great rear for some applications, for others it is DEAD WRONG. And for a 3000lb radial car, that has the potential to go low 5s, like the two cars Bill is talking about. A DANA is the WRONG choice..........period.

Just because you broke an 8.75 in your 9 or 10 second car and "fixed" it with a Dana, does NOT mean that is what everybody needs to do. The proper parts are application specific

Monte

Application, application, application, it all depends on the application. The Dana in my Dart is all I'll ever need. Complete minus brakes it was $1950 shipped from Strange. A CM housing with no ends is over $1200.

Some of the info that keeps getting reposted as gospel is just not so in my own findings.

There are reasons to run either rear. Most are buried in the misinformation posted on here. I have ran a Dana 60 for 20 years. Never bent the housing and it has no brace. I use a lw cover with no links to a brace. When the tubes are welded to the center housing it makes a very strong unit.

The reason to not run a Dana 60 is gear choice when needing a pro gear. You are limited with 4.10 and whatever lower gear may be on a shelf somewhere.

9" is plentiful with any gear imaginable. A lower pinion with more mesh. You may or may not want this.

A heavy leaf spring car never seeing over 1000 LD ft of torquefrom the crank will do awesome with a Dana.

It's a Mopar. Put a Dana under it.