Now that I figured out that I have 2.73 gearing in my car, I was wondering if it would make much difference if I upgraded to 3.23 and kept my auto tranny. I will soon be throwing my tpi setup into it and running hooker headers with a slp cat-back exhaust and I need to know if I should do the gears while im at.

 

difference? obviously. big difference? depends on your definition of a big difference. do you want good acceleration or good gas mileage? it all depends. many people go lower than 3.23 if they're bothering spend the time and the money to do it. i went to 3.42, and i considered it a decent change. if i had gone wiht anything higher i probably wouldnt have been as pleased.

 

I went from 2.72 to 3.23 becase those parts were available at the time. I have an 89 RS with the LO3 (headers, stage 1 chip, functional cowl induction from an 81 Z, and a 700R4. The gear change made quite a difference but it was really a pain trying to get the right speedo gear for the swap.

Ended up doing the swap because I had a broken carrier. Only replacement I could find and afford was a rear end out of a 90 firebird w/ a 6 cyl. My guess is the car had a stick.

Anyways, the swap was the internals into my housing and it works well. No real noticable reduction in MPG and definately more powerful launches. Now if I could only get a posi.

 

Mine had 3.42's. Quick response on street and got good mileage.

 

Spatter1 I just put a 3.42 rear in from a 2.73 rear. They used the old posi but my speedo is off, what speedo gear did you use, I'm trying to figure this out myself.

 

I dont know why you'd ask him since he swapped to 3.23.....but anyway, i used the largest gear they had (45 tooth?) for the gear outside the transmission (driven gear?)....assuming you have the 26.5" (or whatever it is) tires, that will bring you within a couple percentage points (damned close) of accurate. however you will need a new "carrier" for the gear to set on. you should go to your gm dealer, they will be able to figure out the part numbers for you.

 

So i should just go with the speedogear with 45 Teeth, alright. I'll call tommarrow bout the part numbers, So I will need the carrier also? How much more you think that is?

 

I may be mistaken, but I think that there is some info on the speedo gear in the tech section of the site.

I ended up talking to several parts guys at local dealerships. I had to talk to several to find one that seemed to know anything and they did get me all set with a somewhat accurate speedo gear. Unfortunately, ever since I put that gear in the trans has leaked a little out of the speedo gear bore. It is only a small leak but it does add up. I think that I may need to change the drive gear, but I am not a big fan of opening up a trans case... maybe I should go to the trans shop to get it fixed right.

 

Where did you go for the speedogear, what parts provider and how much was it?

 

A dealer ordered it from GM... it was $15-$20 for the driven gear and plastic casing that it sits in. This was about two years ago. I'm sure you can find a GM dealer that can get them... the magic of the Internet has provided us with easy access to huge dealer parts inventories that local dealers may not know or care about.

I replaced some gaskets on my TBI unit, none of my local dealers seemed to have any info about saying that they were discontinued and unavailable... withing ten minutes I found a dealer on the internet that had the parts to me in a couple of days. (Bob Maguire Chevy).

Good luck.

PS. I see that you are in Rochester (I'm in Syracuse), do you know of any local Camaro clubs? How about junk yards with a good inventory? Thanks.