When did gm switch rears? I have a 92 firebird that had 2.73 limited slip, and I put in a 82 Trans Am rear that's posi with 3.08's. Is it a 9 or 10 bolt and does that effect a carrier when I switch to 3.73's?

Thanks

 

Both 82's and 92's would use 10-bolt rear ends. GM used the 9-bolt in some high performance f-bodies from 85-89. Its mostly common in the 87-89 350's. You cant use 10-bolt posi's or gears in a 9-bolt, and vice versa. 2.73 and 3.08 are 2-series carriers, so if you later want 3.73's you'll need 2-series gears. Also the 82 rear end will be English and the 92 rear end is Metric, so you'll have bolt and brake line mismatches...

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1991 Camaro Z28
350 L98 w/ T56 (originally 305 LB9 w/ T5)
318 RWHP, 419 RWTQ
12.803 @ 108.50 MPH (1.932 60')
Member: SoCal F-Bodies
ThirdGen 4-Life!

 

Did all 85-89 f bods with disc brakes have a 9 bolt. I also have a 86 TA SE with disc brakes and posi 3.08's, Is it a 9 bolt? How much better is the 9 bolt? I already put the 82 rearend in I just used parts from the 92 brakes.

 

The 9-bolt is quite a bit tougher.

www.9bolt.com

Jack up your car and check it out.

Theres an old hotrod article that says its tougher than a Dana 44. If that gives you an idea.

 

No, I said SOME 85-89 f-bodies. All the 350's got them from 87-89, and some 305 5-speeds, the ones with the G92 package. All you have to do to tell the difference is count the number of bolts holding the cover on. 9 bolts is a 9-bolt and 10 bolts is a 10-bolt. Also the 9-bolt has a rubber plug in the cover, used for adding the fluid. The 9-bolt is a stronger rear end than a 10-bolt, but its not bullet proof.

 

mine 87 iroc-z has the 9bolt hehehe.. and i hope i dont blow apart my spider gears this summer!. lol

 

9 bolts here too ,87 gta 350 tpi ,and 89 gta 350 tpi transam's,both are ws6 w/rear disc

 

I checked my 87 TA Se and it has the 9 bolt disc ws6 rear so I might steal it for my 92.
Thanks guys for the info.

 

I had the 9 bolt as well.
86 Trans Am WS6 LG4 305 5 speed.

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1986 Trans Am WS6
LT4 350, LT4 Hot Cam, T56, 52mm TB, MSD 6A & Blaster 3 Coil,
LT1 3.42 Posi/Disc Rear, Lakewood LCA's & Adjustable Panhard Bar,
Eibach Lowering Springs, 17x9 WS6 Wheels, T-Tops,
Custom 4" CAI w/ K&N Filter, 160*stat.
Autometer TriplePod with Phantom A/F & Boost Gauges.
High Speed Run: 157mph
Best 1/4 mile run: 14.94@91.67mph This was with the LG4 carb setup.
WS6 Trans Am.

 

If the 9 bolt was so strong why don't they put them in the new f-bodies and why did they stop useing them.

I find pretty stupid on GM's part to but the same dif in f-bodies as they do into 4 banger S10's... What wer they thinking!?!?!

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1987 Red IROC-Z / 305 TPI / TH700R4
Smoke Show Video's
British Columbia - Team F-Body
Pictures...

Edlebrock headers / Bored out Catilitic converter / Flowmaster muffler / 3" exhaust cut out / MSD 6AL Ignition / Hypertech performance chip / 160 Thermostat / Hypertec pulleys / Posi 3.73's / Shift kit (?) / TC Lock-up switch / Dual K&N's

201 rwhp 285 trq.
best time 14.687 @ 93 mph

In the making...
383 forged L98 / Miniram II intake / AFR 190cc heads / Costum grind cam / BBK 58mm TB / Costum tuned chip (4now!)/ 200 shot of NOS to be added later

Expecting ~400rwhp N/A

 

COST!!!!!!

Not just the initial increased manufacturing cost, but the increased spare parts business when the 10 bolts start breaking. It's just business

Miles
Diff Solutions

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88 427 BBC Camaro
7.76 @ 94 (1/8 mile) 10/01
12.18 @ 113 (1/4 mile) 10/99
I have brand new series 3 9 bolt posi carriers and gear sets to 4.10 available for borg warner 9 bolts. Check my web page for more info.

http://www.koolmeister.com

 

Heres some helpful info on replacement parts for the 9 Bolt Australian Borg Warner Rearend....

Christman Interprises 800-499-4327
Ring and Pinion gear set
US Gear P/N 01-878370 $301

Installation kit
Ratech 513-742-2111
RAT-332TK Firebird
RAT-333k Camaro-Firebird