Happy new year everyone. :beers: I was wondering should I install a GM 12 Bolt rear or a 9" ford for my Ram jet 502 camaro I mostly drive it on the street, I just want something strong and reliable. Any help on this would be appreciated.

the design of the stock rear ends? the 9 in. You goin after market? keep it GM.

Do what you want. If it was me I would get a nice Currie 12 bolt or a corporate 14 bolt for big horsepower.

For street driving on street tires almost anything will hold up (even an 8.5" 10 bolt). If you don't have a rear end or parts to start with then, it really is just a matter of preference. If you have some parts for either of the rear ends you mention then go that route to save a few bucks. In STOCK form the 12 bolt is a stronger rear end. If you are going with aftermarket or modified parts then the 9 inch is the winner. If you plan to race (slicks, etc..) or think you will in the future, you might as well build a rear end to handle it.

I would much rather use a 12 bolt. Less horsepower consumption, keeps the car all GM, and a 33 spline NEW Moser 12 bolt is stronger then a 31 spline 9" Tru Track, period. I probably sell 10 Moser 12 bolts for every one Moser 9" Ford lately.

Do a nice Moser 33 spline, Tru track, perfomrance cover, and try to break it!

Thank you for all the info I guess i will go with the Gm 12 bolt.

As a ZZ502/502 owner for the last 6 years, my original 12 bolt is holding up just fine in my street car. But, I used a solid pinion spacer instead of a crush sleeve during my differential assembly. Just my personal thoughts, I feel that a solid pinion spacer and good axles such as Moser's will provide years of great service.

As Frank stated, If you need to purchase a differential, Moser's new 12 bolts are a better choice. And personally, :noway:I hate to see a Ford rear in a GM street car!:noway:

I have seen plenty of 12 bolts pop at the track w slicks and only 1 9 in but it was stock and behind a tubbed bbc Chevelle for 12 yrs. For the street a 12 bolt built up will be fine. But a moderat built 9 in whould be good to well into the 1000 hp range.

Bottom line...........Who wants a FORD rear in a Camaro :sad:


You'll never break a Moser 12 bolt at your power level.


JMO of course.........



bob

... But a moderat built 9 in whould be good to well into the 1000 hp range.

No - it won't :noway:
The rear pinion bearing support will split quickly with the continued input of anything over 500HP time after time with a regular cast iron center section.
I have built and prepared 9" for many years in all types of race cars.
Failure to use a modified center section, like one of the Currie "9+" units, will result in carnage to the unit within a few passes.
Now you're talking about over $1,500 to get to this level, not including big bearing axles, carrier, housing mods and etc ...

The pinion shaft design and construction in a GM 12~14-bolt, or the larger Dana's, is far superior to the best factory supplied 9" units and will not fail with input levels well into the 700HP range.

You'll spend less getting a properly prepared 12-bolt Moser set-up than trying to do an equally strong 9" anyday.

Bottom line...........Who wants a FORD rear in a Camaro :sad:

bob

That reminded me, I should change my signature... there are no FORD parts in my 9" (Moser housing, Strange center yoke and axles, TrueTrac).

I have run a factory 12 bolt with a spool and 33 spline axles in my 900 HP, 3450LB 1969 Camaro Street Racer that runs bottom 9s, 1.35 short times, and have NOT broke that rear since 1998 when I built the car. It has 500 runs on it (conservatively) and 5000 street miles (conservatively). I have killed one set of street gears, and we did put C Clip eliminators on it. Otherwise it is stock. And Moser is stronger then the stock one.

To build a stronger 9" would require using a spool of Detroit Locker, which both SUCK on the street. otherwise your stuck with the smaller 31 spline differentials.

Thank you all for that helpfull info, I guess I will stay with GM parts.

I will be the odd guy.....I went with a Currie 9". Very happy so far. I like the idea of being able to swap 3rd members anytime I want too and no c clips to fail.

I will be the odd guy.....I went with a Currie 9". Very happy so far. I like the idea of being able to swap 3rd members anytime I want too and no c clips to fail.

I went with a Moser 9" housing and Strange 3rd member. I didn't want C-clips, and didn't want C-clip eliminators (autocross), and didn't know I could get a 12-bolt housing with 9" style ends/bearing.

Both rear ends can get the job done. Buy what will work for you. You can build a 9" and not have a single Ford part in it. Don't let that be the deciding factor. Like I said before if you are running regular street radials it really doesn't matter so don't get too carried away. The tires will spin LONG before you break anything. It is true a 12 bolt will take less power to turn. If you go that route get some sort of positive axle retention (don't rely on the c-clips).

Don't get too caught up in the spline count either. Sure with stock axles it's a big deal. Once you start getting into alloy aftermarket axle, they are so much stronger, you may be fine with 28 or 31 spline. Talk to your axle company of choice and see what they suggest. There are so many other things that haven't even been discussed that make a huge difference (weight, auto or stick, converter, gear ratio) all effects how much load the axles will see.

I went with a Moser 9" housing and Strange 3rd member. I didn't want C-clips, and didn't want C-clip eliminators (autocross), and didn't know I could get a 12-bolt housing with 9" style ends/bearing.

Our most popular F Body Moser is a 12 bolt with Big Ford 3.15 bearings and chevy brake flanges. We usually load them with 33 spline Tru track and the beefy Performance Cover.

Still going off what I see, and I have seen more 12 bolts break than 9's. Sounds like at your power levels it will never be an issue so I would go the cheaper. I have a 9 in but it is set up and Im pulling the wheels of the ground :)

My thing was I really liked being able to have 2 3rd members. One for the strip and one for long distance cruising like a Power Tour. My current set up is nice with 3.55's and the GV overdrive. But if I was going super long trip a open 2.73 or 3.08's would be sweet and dirt cheap.

Had a 12 bolt built, worked great excepted c clips caused fluid leaks alot. went with a strange nine inch, holding up great with my blown 502 and stick shift. Starting to wonder if it is breakable with the way i drive:o

Dana 60.