As far as I understand on the Tech Data page, my car has 2.73's. How much of a difference would I notice if I bought something different? How much would gas mileage change?(not that that's too much of a concern)

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Take 'er easy, and if
she's easy, take 'er twice!!!

 

youll notice a big difference in acceleration
i went from 2.73s to 3.42s.. the car feels way more responsive, because it is

gas mileage wont suffer unless you do alot of highway driving where the rpms on the highway will be higher than they were
if you drive just around town you might actually gain some mileage

 

I recently went from an open rear with 3.08s to a posi with 3.73s. I can tell you that the car does seem to pick up quicker and definetaly goes through the gears quicker, but you won't launch much harder. I was shocked when I went to launch with my posi/3.73 rear and it didn't feel too much stronger than before. Whereas my bro's 5.0 Stang launches extremally hard.

According to Steve Spohn, we need better torque arms to plant the rear. I'm looking forward to doing this soon.

Just don't expect too much of a better launch,

Jason

 

I went from an open 2.73 to a posi 3.73, and I can finally roast the 1-2 shift. I love it. Top end totally sucks. I used to cruise at about 70-75 MPH in 4th gear @ 2000 RPMs, now at 2000, I'm at 55! I also have to put the shifter into OD at the 1/4 mile instead of leaving it in Drive, since I now readline in third around 75-80 MPH. It takes alot from the top end, and gives it to you in the bottom. 3.73s was a good choice for me, since I am into acceleration, not top end speed.

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If you live in Southeastern US, check us out!
South East Thirdgen


ASE Master Tech + L1
Savannah, GA

'87 Trans Am
S/D TPI retrofit including functional PassKey, 22# injectors, Whatever chip I feel like burning,
JET AFPR, Ported Plenum,
TB Coolant Bypass, Custom Cold Air,
SSM SFC, KYB Shocks, Boxed LCAs, Wonder Bar,
8mm Accel wires,
Flowmaster Exhaust,
16" GTA rims,
Corvette Servo,
-->14.97 @ 94.9 MPH<--

'97 Bonneville SSE

 

I think it depends on what you want. I'm more interested in 0-60(or 70!) than 1/4 mile times. For me, the 3.73's work great. The car is a real handful! It's very hard to launch on street tires. It wants to spin the tires too much! If I'm already moving, or launch without spinning, I'm gone! On the highway, I can pass people with ease in fifth gear without downshifting! If I downshift to fourth, watch out. As long as you're not trying to top-end the car, the lower gears work great! I will add that I've never had my car on a dragstrip.

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1989 Trans Am, 305 TPI 5-speed, T-Tops(love 'em),4-wheel disc, 3.73 posi

 

can someone please tell me the difficulty of switching gears and also how to switch them

 

GMtech, your tach is way off. With 3.73s and 26" tires, 5000rpms is 103mph. You run the 1/4 @ 95mph. Unless you are running a 4500 stall converter you woulnd't be redlining.

V6 3.1 - changing gears isn't THAT hard, but getting them set just right IS. If you had to ask this question then you should not be trying to do this yourself. Try reading a manual on it and see if you're comfortable with the measurements that need to be done. Reason for the caution is this, if the gears aren't set right, it will destroy itself in short order.
...ed

 

I agree with Ed on GMT's tach being, or he has some nasty tranny slip going on. The math just doesn't add up. With 25" ACTUAL ROLLING diameter tires, you'd hit 5000rpm at about 95-96mph. Those are small tires as the example, too, as you are probably at around 26" dia or 27" dia, which would give you 5000rpm speeds of ABOUT 98mph and 101mph, respectively.

 

Oooops, sorry, plug 4500 instead of 5000 into the equation and see if that doesn't pan out. The tach "yellow lines" I guess you could say at 4500, and I usually don't push it past that (its a tired old 305).

------------------
If you live in Southeastern US, check us out!
South East Thirdgen


ASE Master Tech + L1
Savannah, GA

'87 Trans Am
S/D TPI retrofit including functional PassKey,
22# injectors,
Whatever chip I feel like burning,
JET AFPR, Ported Plenum,
TB Coolant Bypass, Custom Cold Air,
SSM SFC, KYB Shocks, Boxed LCAs, Wonder Bar,
8mm Accel wires,
Flowmaster Exhaust,
16" GTA rims,
Corvette Servo,
-->14.97 @ 94.9 MPH<--

'97 Bonneville SSE

 

This is something that really should be done by an experienced shop. The equipment needed to do it right (some techs experienced in other areas doing it at home not withstanding) costs just about what a shop would charge you. If you don't get it right, you just ruined a set of new gears.

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R. 2.93 limited slip. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 w/LB9 block, ZZ3 cam and intake, WP 305 heads ported & polished, Hooker headers & y-pipe, 3" Catco cat).
57 Bel Air, my 1st car. 0.030 over 396, Weiand Action+, Edelbrock 1901 Q-Jet, Jacobs Omnipack, 1-3/4" headers, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, 3.08 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Best 15.1 @ 5800' Bandimere. Daily driver while Camaro was being put together.

 

It's pretty interesting.. my Iroc has a 3.70, it's great off the line, but runs out of steam at about 75. But on the other hand, my '80 Camaro has a 350 with a TH350 and a 2.73 axle. It sucks off the line (for a v8) but LOVES to play after 25mph or so. It's all a tradeoff. Ever consider like a 3.23 or 3.42?

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1980 Camaro, '88 Police 350 engine, Headers, full exhaust, completely redone, my baby!
1988 Iroc-Z L98, MSD 6a, Accel coil, K+N's, Airfoil, Coolant Bypass, Flowmaster, Gears, Late model Bose, I like the 80 better