I've searched the archives but would like more specific answers, if possible. I'm currently running stock 3.23s with a 5-speed.

1. Is the seat of the pants difference worth the cost for a daily driver (I'm mostly a highway driver)?
2. What kind of gas mileage should I expect?
3. Noise?
4. New or used gear sets?

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[This message has been edited by JamesC (edited November 26, 2001).]

 

It really depends on a number of factors. Especially the engine you have, and what you are looking to do with the deeper gears. If you occasionally visit the track, 3.73 gears are nice to have, but I don't think its worth the compromise if you are worried about gas millage. I am currently running a T5 with 3.73 gears on my LG4, and I get terrible gas milage (7-10 mpg).

 

I've had factory 3.73's since brand new. The car gets 21 MPG on the highway, and still runs the quarter mile in 14 seconds flat.

I have 136,000 miles on the ol' T/A.

As for noise, I use Richmond gears. You can hear them whine. However, since I've owned the car for over a decade now, the noise has never been objectionable.

If I were you, I'd just buy new gears. Buying used is asking for trouble IMHO, unless you know the seller really, really well. You might end up spending $300 to have them installed just to find out that they are junk and whine like a 4X4.

Lastly, dont be afraid of the 3.73's. They are not that radical! They WILL indeed make a difference during daily driving.I commuted to work on I96 for 18 months, and it was a 55 mile dive one-way. Thus, I rapidly put 40,000 miles on the car. Its only 2600 RPM at 70 MPH, by the way. However, if you have a tuned-port engine, you might want to consider a 3.42 ratio instead. The 3.73 is a good gear for engines that can power up to 6000 RPM. The 3.42's are more suited for engines with practical limits of 5K, such as the TPI engine.

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[This message has been edited by ws6transam (edited November 26, 2001).]

[This message has been edited by ws6transam (edited November 26, 2001).]

 

I agree with WS6transam.3.73's in my RS are just what the doctor ordered.Nothing to be afraid of,especially if you have an overdrive transmission.
I definetely wouldn't buy used gears unless you're absolutely sure they're ok.
My Richmonds whine a little too, but not enough to bother me.
When I was in high school(20 years ago), I had 4.88's in my 68 Camaro.Now those are some steep gears!I could take just about anything light to light, but couldn't drive it on the freeway much.
-Rich-

 

I had a set im my camaro but IMO it was to agressive especially when your trying to hook up at the track. 3:42 from now on. You should be able to run 3:73's with your 5 speed no problems. A great compremise gear is 3:42. Like mentioned 3:73's arent "killer" deep gears, but they arent great for all apps.
SSC

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85 Camaro Z28, Cowl induction hood, Black-355/TB400,3:42 posi, Tons of goodies but if you ask, "Its stock"
82 Firebird, White, red in six months-355/TB350,3:42 Powertrax posi. Not an insane amount of goodies but it runs like a motha!
76 Chevy C10, Firemist blue, 355/Muncie HD 3speed,3:73 TorqLine posi. Show me another 12sec@4800ft SBC street truck??
91 GMC 1500 Sierra 4x4, Red, Was 4.3 now the proud recipient of the Firebirds LG4. 305/5 speed.
56 Buick Special, OG Blue&White, V8/auto. Maybee one day I'll get it going.

 

I went from 2:73s to 3:73s. Gears and install kit= $300, labor=$150, posi unit(something in the old unit broke)=$150. For the price I definately wasn't impressed. My mpg hardly decreased at all. Driving on long trips from home to college in the mountains isn't that bad with OD.

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3:73 Posi Rebuilt 700R4
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I've had every gear you can imagine in some car I've had at one time or another. My 83 car came with 3.73s (as did some 70s 350/350 Z28s I had back then).

• 1. SOTP is major. One of my little brothers had a 84 LG4 Z28 with 3.23s, and came up with a rear out of a L69 car, with 3.73s; it was like an instant 25% shot of torque and HP around town. It didn't hurt performance on the highway either.
• 2. My gas mileage with the stock L69 and its stock 3.73s was similar to ws6's.
• 3. No noise, any more than any other ratio of the same brand, when properly set up.
• 4. Definitely get new ones. They're cheap, about $200. Not worth the trouble and expense of dealing with failed used ones, unless you can check out your prospective used ones while they're still driving around.

I would recommend GM Motive gears, they're quieter and easier to set up since virutally every time you can just stick a stock thickness .035" pinion shim in, and they'll be perfect. As far as ease of set-up it's hard to beat no set-up at all. You can assemble the rear yourself and skip the labor charges. They're not as strong in a racing application but IIRC that's not what you're building anyway.


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"So many Mustangs, so little time..."
ICON Motorsports

[This message has been edited by RB83L69 (edited November 27, 2001).]