jeremychapman

I have a 1994 Pontiac Firebird Formula A4 car. My car has 2.73 gears in it. My list of mods that I have, are a TPIS airfoil, Borla 2 3/4 Y pipe, SLP CAI, Hooker aerochamber exhaust, and a Carsound high flow cat. I would like to change the gear ratio in my car. I would like to put a good used 3.42 rear end out of a 6 speed car in my car, but the local salvage yard where I live only has a 3.23 rearend out of a 95 Transam automatic car. They are asking $450.00 for the rearend with only 60,000 miles on it with a 90 day warranty. Will this 3.23 rearend be close to the 3.42 rearend as far as performance on the street and at the track. I do not want to go any higher than a 3.42. Also do you think my car will outrun a stock A4 LS1 with these planned future mods and possiby run 12's in the 1/4. Thanks, sorry for my thread being so long. This is a great website.

1. Crane 210 224 479 518 lift cam also known as the 227 cam
2. Hooker coated shorty headers
3. PCM for less programming, 160 thermostat
4. Comp Cams Pro Magnum 1.5 roller rocker arms
5. LLoyd Elliot stage 1 p&p cylinder heads- flow numbers 255 intake cfm 180 exhaust cfm using stock 1.94 1.50 valves
6. Edge 2800 stall converter
7.SLP CAI
8.TPIS air foil
9.Carsound high flow cat
10. Hooker aerochamber exhaust
11. 3.23 gears

Z28WannaB

Ditch the hooker shortys and get Pacesetter LTs. Get 1.6RR, and just drop in some 3.73s. It doesn't go into OD until triple digits.

Buy a gear set and have it installed, that way you don't have a ragged out 6spd rear end.

- Z28WannaB

MyShibbyZ28

Get a bigger cam. And don't waste your money on shorty headers, get long tubes. You'll love them. 1.5 rocker arms, no, get 1.6 rockers. Also if you just want to go all out, get LE3 heads, with a bigger cam, and a bigger throttle body, like 52mm or 58mm. 1.6 roller rockers, long tubes, and port the intake. just my 2 cents.

snakeatinZ

to awnser your question... Yes, That set up would dominate a stock ls1. Go with myshibby's plan and you can Own ls6's

FastZinTennessee

1) Instead of that, get the HOTcam kit. It comes with a bigger cam than that, 1.6 ratio roller rockers, springs, retainers, locks, shims. In the $400 range, it's really hard to beat. If you're worried about emmissions it will still pass no problem even with a mail order tune, I know from experience. You will probably want to ditch the springs it comes with in favor of some better ones.
2) Unless you're dealing with SLP, MAC or AS&M I wouldn't bother with shorties. The Pacesetter long tubes work well and are inexpensive.
3) PCMforless did a fine job on my tune. I still ran the stock thermostat, although a cooler one shouldn't hurt anything.
4) If you get the HOTcam kit, it comes with roller rockers already.
5) Lloyd Elliot does very good work, probably the most popular choice on here for porting. You can't go wrong with him.
6) I've been hearing good things about Edge converters lately. If I didn't have a Midwest already I'd probably pick one up.
7) Isn't the SLP intake the chrome flashy one? Unless you are getting it for the looks, they all perform about the same, and I'll bet you could get a K&N for cheaper.
8) Skip the airfoil. After I did my cam and headwork the car would not idle because the airfoil blocked the IAC inlet. After removing the airfoil it idled fine.
9) I've had good luck with Random Technologies, and hear they are one of, if not the best. I haven't heard much about Carsound though.
10) That would be a good exhaust, as would Magnaflow, or Borla if you've got the extra coin laying around.
11) I personally liked my 3.23 gear set. I shifted at 6200, and that wound 2nd gear well over 80. It seems like a good gear for the 1/8th mile, but I never ran my car on the 1/4 so I don't know about that. The only advice I could give you is this- don't guy a whole rear end. Just get the 3.23 or 3.42 gearset and have someone competent install it- and I mean competent. These rear ends are notoriously weak, there is no room for error if you want it to last. This way you have new gears instead of a used rear end. Also might want to invest in a stud girdle while you're working on the rear to help it live longer.

white/blackss

i have a 3:73 gear set in my 1994z with the a4 and it`s perfect, i can still travel on the freeway and drive in the city.

it made the biggest improvement in my car and i already had the 3:42 stock rear end.

i also agree to just get the gear set and have it installed by a professional, it will save you lots of time/money

good luck on the new rear end , what ever you pick im sure you will like it

Z28WannaB

Go with a Moroso cold air intake. Moroso is the cheapest, also watch where you buy your parts. You would think they would all be competitive but I've seen some places selling Moroso 169.99 brand new, versus others selling it 189-199 brand new.

Or you could just wait til someone lets go of their CAI but they usually go for like 125 used because there is no wear on an item like that and pretty much everyone at least wants an intake.

I would just say buy one new from a website that has it listed cheap.

And once again go with 3.73s you won't regret it.

- Z28Wannab

MyShibbyZ28

Or if you want to spend the extra money get an SLP CAI, they have a max flow of about 1128 CFM.

GT KILLER

Hmmm...my dilemma was between 3:42's and 3:73's.......and I'm still undecided, LOL.

gt_biker13

I have 3.23s and at 70MPH it revs a little over 2000 RPM in OD, i dont see how 3.73s would be good on the freeway. Also, the lingenfelter CIA is the cheapest at 159.95 http://www.lingenfelter.com/store/ln0041.html

1racerdude

A 4.30 is no problem on the Interstate in OD..

Bersaglieri

3.23's are an awesome gear, I wouldnt be changing mine if it wasnt for a buddy selling his 3.73 rear end from his Z28.

I agree with the Hotcam kit, for what your looking at doing it would be a much better route for less money.

-Dustin-

BiGGinZ

If you are looking for track times or beating a buddys car on the street go with 3.73's if you just want more fun around town go with 3.42's. But dont just upgrade to 3.23's not worth it IMO when you can get 3.73's for just as cheap. You can find some used 3.73's and install kit for like $200 then just pay to have them installed which is probably like $300-$500, not sure though never had it done.

BiGGinZ

1racerdude

I charge $150.00+parts for a gear install,a 9" is $200.00+parts.Don't know what the rest of the world charges.

Zepher

go with 3.73's.
on my slow Formula, I cut .5 seconds from my ET going from 3.23 to 3.73 and picked up 3mph when it was an A4.