So right now my car has a 10 bolt & 3.42 gears. I wanna see what I can get out of my Camaro NA & stock internals. Looking to dip into the high 11's. I've been deciding if I just wanna throw some 4.10 gears in my rear & start the count down until it explodes or spend the money & get a 9" or 12 bolt. I saw a thread while back comparing the two, pros & cons but couldn't find it. So I'm just wondering what are the pros & cons to each.

I use my Camaro as a DD, will be going to the track quite a bit, & will be launching it pretty hard street/strip. I will be NA stock internal running full bolt ons only for a while until I get to where I wanna be then go with a H/C package. But that's in the future. I wanna get a rear end, gears, & clutch before I buy a cam. Thanks!

 

Since you're a M6 daily driver I'd say go with the 9" or S60, posi, and some 4.11's. Search the threads and look at the custom 9" and S60 setups some of the vendors are offering.

I've had great experience with the Moser 9" in the past on a different TA. The 4.11's will really wake your car up. I'd upgrade your clutch too before you start with the H/C upgrade.

 

Yes the 9" is the way to go for a 6spd. I have been researching and asking around myself and the 12 bolt is going to make noise after your first launch at the track. The 12 bolt is good for the automatics. My stock 10bolt is on its way out and I am in the process of saving the $$.

 

you gotta look at the rearend and suspension upgrades on your car as being an investment. the biggest issue here is doing it right the first time so your hard earned money is spent right.
the known fact here is that you have a M6 car, and plan on power upgrades and track use so the best thing for you will be the S60 or 9" rearends. the 12 bolt is known to have other issues than just picking up gear noise after the first few hard launches.

The S60 is a great rearend and comes completely assembled, ready to bolt in the car. the housing was designed specifically for the 82-02 f-body and is super strong in its basic form with features like 35 spline axles, Truetrac diff, and 9.75" ring gear. only drawback is it's heavy weight, new driveshaft required, and no powdercoating available.

the 9 inch is probably the most popular rearend choice as there are a few different styles and manufacturers of them. there are several diff unit choices, housing options, weight reduction possibilities, powdercoating options, etc. it will be lighter than the S60, and the fabricated 9 inch we offer can actually be made lighter than the stock 10 bolt if so desired. the stock driveshaft can be reused with a 9 inch, but we strongly suggest the use of a good aftermarket shaft from Strange or PST as the stock shafts are weak at best. the 9 inch can get costly if you load it up with options, but you only want to do the rearend upgrade one time and be done with it.

both rearends are available with 3ch abs or 4ch abs/tcs systems, and we can do aluminum center sections with the 3ch abs where others will not. Midwest Chassis & Performance is a direct dealer for Strange and Moser and we manufacture the ever popular fabricated 9 inch package for the 82-02 f-body cars. With having sources from many different manufacturers we offer the most options and the best pricing on any rearend package you can think of. Pm or call us for more info or a quote.

 

Alright sounds good.. Thanks guys appreciate it

 

Reading all this about 12 bolts and 9" Fords have me wondering what's up. Ran a 67 big block for years at the track with 4.88 gears and slicks. Car was 3180 pounds ran mid 11's and had few problems with the drive line. Never had a noise problem with the rear gears, never broke the stock Posi. Broke a few ring and pinions and one passenger side axle in many hundreds of runs.

Also had a record holding 64 Chevy II, another four speed car with 4.88 gears and a stock 12 bolt out of a 68 Camaro. By class rules it could only run 8" slicks with a minimum of two treads. Ran 12.50's all the time and never hurt the rear axle.

More recently I had a 69 Nova that held the AHRA record for 4 years. It ran 12.0's all the time and never broke the 12 bolt. But it was a Powerglide car, and they are easier on the rear end.

Now, I also have 9" Fords. One in my 10.90 car has broke twice. It has 4.89 gears and a Detroit Locker. So far it's broke the case and chipped the ring gear. The case broke on its fourth pass at the strip. Broke right where the case holds the small bearing at the end of the pinion. The case has to be ground down to clear 4.89 gears and that's where it broke.

My 73 Nova, also 4.89 ratio, runs 12.0 and it's ring and pinion is starting to whine when you let off. So far the only failure has been the pinion yoke. It has been pounded a bit but nothing like the 67 Camaro I beat with 7,000 RPM clutch dumps.

I would not sell a 12 bolt short. Right out of the factory it's stronger than a 9" Ford with stock parts. (Other than the drag pack cars.) Its weak link is the Ford LS unit. It's a junk design and breaks if you shock load it. And unless you are lucky enough to find a nodular case you have to buy a Strange or other after market case and pinion support.

If you take a 12 bolt and a 8.8" Ford apart and look at the parts you'll see where Ford got the idea.

Al

 

Al,

You have valid points with what you said, although there is more to take into consideration. Where the 12-bolt has its shortcomings with the F-body is due to the casting for the center having the torque arm mount integrated to it. I'm not certain why but the 12-bolt does not do all that well in the torque arm configuration.
The S60 (Strange's Dana 60 copy) does much better. I believe the difference might be due to the stronger and heavier casting of the S60.
Maybe Eric from MWC will comment on this, He has lots of experience with both of these rear ends.
Carl

 

The 12 bolt rears that are available for these cars is a step in the right direction. The 12 bolts are well known for being a stout rear that was a factory option back in the day in many performance cars. You can have a 12 bolt in an early Chevelle, Nova, Camaro, etc, and beat the snot out of it and not hurt anything. Put a 12 bolt into a late model f body that uses a torque arm, make a couple 4000 to 5000 rpm launches at the dragstrip, and I can just about guarantee you'll have a lot more gear noise on the way home. The torque arm seems to distort the housing on the 12 bolts, and it seems to happen to all the brands of 12 bolt rears. This does not happen to the 9 inch rears, and there is no price difference between the 12 bolt and nine inch rears. As the horsepower in our engines keep escalating, most people these days go straight to the nine inch rear. The 9-inch has an internal rear-pinion support that also supports the gear end of the pinion to limit gear deflection under high torque loads. This seems to be the major reason why the 9 inch doesn't start whining after high rpm clutch dumps, when the 12 bolt will pick up noise. The 9-inch locates its pinion gear lower on the ring gear to improve tooth contact, better the 12 bolt does. The 9-inch also has a 0.125-inch larger ring-gear diameter and internal pinion support than the 12 bolt. Bob