Thinking of upgrading the gears

I have I think 2.72's or 2.73's (don't remember) in the 96 (limited slip) and I'd like to go with 3.42's. I asked my facebook friends (mostly f-body guys) if anyone had some and I was asked what series. How do I find out this answer?

I believe it is 2.93:1 or 3.23:1 in the tow pack car. Non tow pack are 2.56:1.

I took mine to 3.08:1 and now to 3.73:1. I would suggest the latter.

BigBlackBeaSSt wrote:

I believe it is 2.93:1 or 3.23:1 in the tow pack car. Non tow pack are 2.56:1.

I took mine to 3.08:1 and now to 3.73:1. I would suggest the latter.

Why not 3.42's? I still want to retain a little bit of my gas milage, I just want a little more low end grunt, I'm probably also going to be doing a 3000-3200 stall.

nstg8r wrote:

BigBlackBeaSSt wrote:

I believe it is 2.93:1 or 3.23:1 in the tow pack car. Non tow pack are 2.56:1.

I took mine to 3.08:1 and now to 3.73:1. I would suggest the latter.

Why not 3.42's? I still want to retain a little bit of my gas milage, I just want a little more low end grunt, I'm probably also going to be doing a 3000-3200 stall.

In my experience 3.42 and 3.73 will not change the fuel mileage much at all. My 3.08's to 3.73 swap did not show much change if any. The 3000-3200 would be counter intuitive for fuel mileage. I would guess around town that would hurt you much more than 4.10 gears. If you retain lock up it should not effect things on the expressway.

I am looking at doing a gear swap in my 95 Caprice SS Wagon. I am planning on going to the 3:42 gears over the 3:73. Currently my wagon has a 2:56 open end gear.. I am going to a Detroit TruTrac LSD.. You will need to find a aftermarket re-lector to keep the ABS working..

You can get all the parts from Randy's Ring and Pinion..

I found a 3.73 R&P set brand new along with a brand new reluctor gear for 175,just have to go pick them up.

Flasheroo wrote:

I found a 3.73 R&P set brand new along with a brand new reluctor gear for 175,just have to go pick them up.

Did you just find them on C/L in VA beach?

Dont you do it Robert,those are mine!He has had them long enough!

Flasheroo wrote:

Dont you do it Robert,those are mine!He has had them long enough!

Bwahaha - J/K I wouldnt do that to a fellow Longroofer, you might as well kit the install kit while your at it, thats pretty cheap for what hes asking for it

Wih the exception of the reluctor ring,he wants retail for everything.I could buy the R&P for
a lot less if I changed brands.If I eliminate the reluctor ring I could save a lot more money.

I switched from 3.08:1 (stock in 1993) to 3.42:1 last year. I have enough horsepower (about 450) to spin the wheels and launch without the need to use a set of 3.73:1

Only my opinion for my car, and may not translate well to other vehicles.

lakeffect wrote:

I switched from 3.08:1 (stock in 1993) to 3.42:1 last year. I have enough horsepower (about 450) to spin the wheels and launch without the need to use a set of 3.73:1

Only my opinion for my car, and may not translate well to other vehicles.

Have you had your wagon on a dyno or is this just a guess?

nstg8r wrote:

I was asked what series. How do I find out this answer?

If you have a 96, you don't have 2.72 or 2.73 gears. You either have 2.56 or 2.93. 2.56 has a series 2 carrier. 2.93 has a series 3. The people were asking because if you have a series 2 and want to slap on gears meant for a series 3 (i.e. numerically higher gears) you will need a ring gear spacer. Not really relevant if you are changing the posi at the same time.

BigBlackBeast wrote:

In my experience 3.42 and 3.73 will not change
the fuel mileage much at all. My 3.08's to 3.73 swap did not show much
change if any. The 3000-3200 would be counter intuitive for fuel
mileage. I would guess around town that would hurt you much more than
4.10 gears. If you retain lock up it should not effect things on the
expressway.

I've used 3.42 and 3.73s. In my experience 3.42s do yield better highway and overall gas mileage. About 1-2 mpg. IMO, the minimal difference in 1/4 mile time doesn't justify the mpg loss for a DD. Plus you don't run the risk of encountering driveshaft vibration. For a real daily driver that regularly gets taken on the highway, 3.42s get my vote. If you don't do much highway driving, then 3.73s are a good option.

Do yourself a huge favour and be realistic with your intended usage. Unless you are going to see the track several times a year, a 3200 stall RPM converter probably isn't required. 2800 would probably better suited and more real-world street friendly. Don't cheap out on the converter: the converter, not the gears, is what will make or break your combo. A 9.5" Yank, Vigilante or Edge would all be very good options, with Yank being my personal favourite. You will not enjoy driving a car with a cheap converter.

Jason,I have a bone stock 305 in my 91 OCC and am buying a set of 3,73 gears to install.Car is
never raced and is only driven rarely on the interstate for short periods.Figured the 3.73s would
help the intown performance as well as the mileage.Now that you have brought up TCs,I am
having second thoughts.Your opinions here will be greatly appreciated.
Thanks

Should be a fun car Jim. A car with higher (numerically) gears and a stock TC is still fun to drive. It won't feel "mushy". I should have specified a "cheap high-stall converter" will make the car unpleasant around town.

Thanks Jason a bunch!

I went from 2.93 to 3.42's with Jade. I have had 3.73s before...but really found 3.42 to be just right for what I need.

Give this calculator a try, input your specs to find the variance in the RPM from the different gear ratios. Have fun!

lakeffect wrote:

I switched from 3.08:1 (stock in 1993) to 3.42:1 last year. I have enough horsepower (about 450) to spin the wheels and launch without the need to use a set of 3.73:1

Only my opinion for my car, and may not translate well to other vehicles.

Do you still have the 3.08? Want to get rid of it? I have a 2.56 open, and want a 3.08 with posi (or limited slip). Tired of it 'hunting' (either TC locks up, or unlocks) going up even the slightest hills. Plus, I want to do some mild towing with it, so the 3.08 will be good for me. I still want to retain some gas mileage.

John[b]

gmtech wrote:

Give this calculator a try, input your specs to find the variance in the RPM from the different gear ratios. Have fun!

That's a good link, but I have an easier way of determining the right gear ratio. If you know what your car already does, with it's current ratio, then it's just simple math. I have 2.56 gears, and at 70, I run 1500 rpm. So, to determine what rpm you would go with different gears, then take your 1500 rpm's, and multiply it by the gear ratio you want. In my case, I want the 3.08 gear, so 1500 x 3.08 = 4620. Now, take the 4620, and divide it by your current gear, 2.56. That equals 1804 rpm! So, by going up to a 3.08 gear, you would only be going up 300 rpm at 70 mph. I would like to keep the rpm's as low as possible, going down the road, for maximum mpg's. Even if you went with a 3.42 gear, your rpm's would only be 2003. But for me, I believe just going with the 3.08 gear would do me the best, in terms of towing, and gas mileage.

John[b]