Ok heres the deal...i have a 92 RS with a 305 TBI 700r4 tranny(just rebuilt with vette servo, and tq converter) Flowmaster 3in exhaust. Other than that its pretty stock. Now i just bought the car 2 months ago and all that was done already. I replaced all the tires with some yoko's and it peels in second. I was thinking about doing some gears but i wanna know your opinions. Like i said there isn't much moded yet, but during the winter i'm going to replacing the 305 with a 350 TPI. I would like to go with eaither a 3.73 or a 3.42 but i'm not sure. Is there that big of a difference? I don't do much highway but there is the occasional. My question is which are the gears for me? I'm also not sure if i have a 10 bolt 7 1/2? Anyone who know what i should be looking for would be a huge help...Thanks in advance.

 

I beleive it is a 7.5", but im not positive, i run 3.42s in my car, i love them, they were a great improvement over my 2.73s, Mpg isnt much worse either, and highway isnt to bad either.

 

If it helps, I was going to put 3.73's in mine, but after reading a couple of posts about how they were too much for a streetable car, went to 3.42 gears. That's what I plan on doing one of these days.

 

everyone has opinions. don't let one mans gospel influence
your decisions.

3.73's will work fine in a street car, but if you lay into it hard
you'll bust traction, easy. personally i'm going to use them
for my street/strip car in a 9" or 12 bolt.

but i'm not too much into rears yet, so if my termonology
is botched, forgive me. still learning, we all are.

don't run anything larger than 3.73's in a street car, they're
definitely the limit, but provide huge torque. 4.10's will be
unbearable.

as far as MPG goes, with the right tranny, you're set.
my next setup will have a .62 6th gear, with 3.73's on 17 inch
tires that brings me to 1828rpm at highway speeds (80mph)
which is damn good on gas mileage.

most of the in city speed-limits around here is 40, everyone
does 45. my third gear is 1.43, so in third gear, doing 45
i'm only at 2372rpm. which isn't bad at all on gas mileage,
go to fourth (1.00) puts me at 1658rpm, and in fifth (.80) i'm
at 1327rpm, but that's where I would begin to bog, since
the low speeds coupled with the gearing ratios would not
be able to produce enough torque at that speed to keep the
car moving eaisly.

It's not all about just the rear end gearing, you have to take
into account your entire drive train to factor what is "too much"

3.73's will put alot of torque to the ground, and on street tires
you won't be able to punch it very often. I believe once
I get my setup built, i'll really like it.


Most of the time, your gut feeling will be more right than your
brain's thought process. ever get the feeling that a cop is
around on a hilly back road where you normally speed, but
you just decide to take it easy this time, you come over a hill
to see a cop blow right past you, you wouldn't have seen him
in time if you were speeding.

I've done that several times, felt a cop before i've actually seen
em, trust your instinct; everyone has strong opinions on everything
so it's best not to get hung up on one persons word, think
for yourself. read a few more posts, and don't just go looking
for the bad things on a subject, everything has two
sides, one good and one bad. you have to account for
the both when considering a part or how to built your setup,
consult with your instinct to see how it feels, then decide if
you agree with it. when in doubt, step back and replan, don't
make rash judgements, it'll cost you money.

 

Thanks for the opinions guys...now one more question. How much am i looking at? I can get the gears from summit for under 200 but what about the speedo gears? i don't know where i could get those or how much they cost? I'm still not sure weather i'm going to go with the 3.73 or the 3.42 but i don't think there is a great price difference. Thanks again for everything, you guys have been a great help:hail:

PS anyone know about how much i would be looking at for install of the gears and a posi unit? Thanks

 

speedo gears from 700r4.com - they also have a speedo gear calculator so you know which gears to get
youre gonna need an install kit - 20 bucks is cheapest, 120 is max which restores like the whole rear end
and im not sure how much someone would charge to put them in
zexel torsen can be had for 100 bucks on slponline.com or 95 on ammperformance.com- if thats not strong enough, they have a heavy duty for like 450 or something

 

cool...thanks...but that brings to mind another question. With the posi unit it shows that its a 28 spline and a 3 series carrier. So when i buy the gears i should match that inf, correct? I'm just wondering cause i believe that stock its 26 spline and a 2 series. Or am i looking at the wrong posi unit? Thanks again