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What rear end gears?

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Old 04-17-2007, 08:59 PM
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Car: 88 Formula 350
Engine: 5.7
Transmission: T-56
Axle/Gears: 9" 3.89
What rear end gears?

I have an 88 formula 350 with 3.27 posi in the rear currently and I was wondering which gears would benefit me the most in the 1/4 mile. Mods are in my sig.
Old 04-18-2007, 12:44 AM
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Car: 1990 Pontiac Trans Am
Engine: 355 TPI siamesed runners
Transmission: Tremec T56
Axle/Gears: 12-Bolt 3.73
Re: What rear end gears?

You're pretty much stuck with either what you have, or a set of aftermarket 3.70 gears, which are known to be noisy. You might be able to find a set of used 3.45 gears, but you'll need some luck.
Old 04-18-2007, 07:03 PM
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Re: What rear end gears?

Why am I stuck? I was thinking some 4.10 or whatever.
Old 04-18-2007, 11:56 PM
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Car: 1990 Pontiac Trans Am
Engine: 355 TPI siamesed runners
Transmission: Tremec T56
Axle/Gears: 12-Bolt 3.73
Re: What rear end gears?

You're stuck because the only aftermarket 9-bolt gears easy to find are the 3.70's, and they're noisy. Everything else is either impossible to find, or impossibly expensive.
Old 04-20-2007, 12:14 PM
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Car: 1987 Camaro IROC-Z28
Engine: TPI 350ci L98
Transmission: T56 - Hurst Shifter
Axle/Gears: BW - 3.70
Re: What rear end gears?

Kevin:

Why do you say the 3.70s are noisy? Depending on the brand and how they are setup can cause them to be noisy but not all should be that way. What kind of gears were you running?
Old 04-22-2007, 06:06 PM
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Re: What rear end gears?

Both mine and my dad's whine while driving at freeway speeds, 55-65 MPH. When coasting, or above and below that range, the whine is minimal.
Old 07-22-2007, 11:55 PM
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Re: What rear end gears?

Sorry to bring this back up, but I am able to get rear end gears and what is a good price for a set, and what gears should I get? I looked on ebay and they have a few. Also, what am I looking for? 9 bolt... is that all that matters or are there more details?
Old 07-23-2007, 08:22 AM
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Re: What rear end gears?

Originally Posted by Bullydawg
Sorry to bring this back up, but I am able to get rear end gears and what is a good price for a set, and what gears should I get? I looked on ebay and they have a few. Also, what am I looking for? 9 bolt... is that all that matters or are there more details?
Lot of gear sets are available, but you have a BW 9-bolt rear which was discontinued by GM in 1989. So very few aftermaket parts are out there for this rear. NO 10-bolt parts are intrtchangeable with the 9-bolt.
Old 07-23-2007, 09:17 AM
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Car: 88 Formula 350
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Axle/Gears: 9" 3.89
Re: What rear end gears?

What does the BW mean?
Old 07-23-2007, 09:21 AM
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Re: What rear end gears?

Originally Posted by Bullydawg
What does the BW mean?
Borg Warner
Old 07-23-2007, 10:03 AM
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Car: 88 Formula 350
Engine: 5.7
Transmission: T-56
Axle/Gears: 9" 3.89
Re: What rear end gears?

Okay, so any Bw 9 bolt rear end gears will fit?
Old 07-23-2007, 10:59 AM
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Car: 1987 Camaro IROC-Z28
Engine: TPI 350ci L98
Transmission: T56 - Hurst Shifter
Axle/Gears: BW - 3.70
Re: What rear end gears?

Probably. It takes a 7.75 inch ring gear. I have some link on my computer at home for good places to buy gears for this thing. I'll post them if I remember. I think all I could ever find was 3.70 ratio and they were around $200.
Old 07-23-2007, 05:17 PM
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Car: 1987 Camaro IROC-Z28
Engine: TPI 350ci L98
Transmission: T56 - Hurst Shifter
Axle/Gears: BW - 3.70
Re: What rear end gears?

Here are some link to site that have gears for the 9 bolt. I have not purchased from these sites but the prices seem reasonable. The only ratio available from these sites is 3.70

http://www.jawsgear.com/store/catalo...ath=21_105_116

http://www.ringpinion.biz/index.php?...70f1bccbf7eb68

Not sure if they have gears but they do have parts for the 9 bolt.
http://ratech.stores.yahoo.net/79bogmax.html

http://www.accuautoparts.com/

http://www.ringpinion.com/Default.aspx

http://www.reiderracing.com/gm734.htm
Old 07-24-2007, 02:40 PM
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Car: 1984 camaro z28
Engine: L69 H.O
Transmission: 700r4
Axle/Gears: 3.73
Re: What rear end gears?

couldnt you just get a set of 3:73 gears?
Old 07-24-2007, 02:43 PM
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Re: What rear end gears?

no only 9 bolt gears are 3.70s. 3.73's are for 10 bolts and other rear ends.

but i'd recommend 3.70s for your combo. your setup with that superam will love it. i have 3.42's in my 10bolt and my HSR/L98 combo. it makes peak power at 5050rpms, and i cross the line near 4500 or so. i need more gear and 3.73's would be best.

reider racing has the 3.70 gears with install kit needed (new bearings and such) for $299 last time i checked
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