OK folks, going to 3.42 or 3.73...replies to this post will determine which way I will go!!

The stats: 305 TPI, Auto, around town drivng-90%, highway-10%, gas milage not a issue, fun driving a big issue, not a daily driver, no drag strips, just around town...lets her the pros and cons of each!!

 

I had the 3.42's in my car and went to the 3.73's and then went to the 700R4 and I love that combo. Great out of the hole and with the overdrive, able to cruise somewhat econimcally if I can keep my foot out of it. The 3.73's get my vote..

 

3.73 1 vote
3.42 0 vote

 

I would say if you are running auto with that combo go with the 3.73's.

 

Staying with a 305 or a small cube v8 and the TPI, go with 3:73.

If planning on swapping to 350 or larger and/or dropping the TPI, I would stay with 3:23 or 3:42.

Depends on your end goal

later
Jeremy

 

3.73 3 votes
3.42 0 votes

Ya Jemery, the most I plan after this would be headers and exaust system, planning to stay with 305 and TPI

 

Yeah I just installed the Hooker 2460's w/ their ypipe and catback exhaust and I love it. I paid like just under 800 or so for the whole setup and that was with ceramic coated headers. It took me like 1 1/2 hours to get the old system out and like about the same to get the new headers, ypipe and exhaust in. So like a total of 4 hours with **** and beer breaks. LOL!!

I love it. You should check it out.

Bill

 

i will for sure Bill...thanks for the tip!!

 

Hey man that hood looks bad ***. As far as gears go it all depends on what you want to do with your car. Overall the 3.42s will be better. As far as drag racing goes 3.73's would be alittle better. Speaking from experience its really not a big difference in gears to be honest, but whatever works. Id go with the 3.42's but thats just me.

 

I'd go 342.

 

3.73 3 votes
3.42 2 votes

Tks for the hood remark...not really doing much more than rear gear change, headers and exaust down the road when it comes to mods

 

3.73

 

chiming in again 3.73

 

I say 3.42 for an Auto . If you had a 5 speed like me I'd go 3.73

 

Ya I was going to say 3.73's until I saw that he had an auto.

 

close still

3.73 5 votes
3.42 4 votes

 

If seat of the pants is most important, I vote 3:73
If looking for best all around gear, 3:42

 

ive read somewhere on this site that 3.42's are closer to the ideal gear for tpi/auto, so it gets my vote!

 

3.73's.....

 

Patricktroy

Here are some of the pics of my headers

BILL

 

Another

 

3.73 7 votes
3.43 5 votes

Nice headers bill!! get that engine bay cleaned up


it gotta make a big difference from the stock headers!

 

Nice coating. Should of got mine coated

 

nice looking bay there my friend

 

I have run both gears ratios, It is my opinion that 3:73 works best with an automatic and 3:42 works best with a standard. I currently have 2 cars with a 5 gear 3:73s, I will be changing my high output 85' car to 3:42 and my stock drivetrain 87' car to 3:23 this spring.

 

I just installed a posi unit and 3.73 gears in place of my 2.73 in my 91. At around 75, I am at 2400 I think in OD. The car has awesome take off now. I've been doing a lot of tuning and it jsut keeps getting better. I am still getting about 20 mpg with a 305 TBI.

 

I know man tell me about it. My engine bay is so DIRTY!! Well I am about to deploy to Iraq for 6 months. So when I get back my wife already gave me the ok to spend up to 5K on a paint job. So guess who is tearing the entire car apart to the frame? ME! I will be on the boards though while I am gone.

 

3.42s - unless you have done a lot of mods 3.73s are not going to do much for the car's limited ability to rev.

 

3.42 Good all around gear.

 

3.73 9 votes
3.42 7 votes

like myself, torn between the two, but might go 3.73 just because I am hardly ever going above 80-90 MPH

 

I'm going with 3.73

 

3.73's are so fun but you will be around 2k rpms at 50mph. im sure u can have the same amount of fun with 3.42's and keep the rpms down a bit

make sure u tell us what you go with

 

3.42 Car will not be any faster with 3.73.

Car is rev limited. where it makes power 0 to 4250 rpm it will not know the difference in the gears.

Rev any faster than that and you are just wasting time.

This may be wrong, BUT I have run both with a stock 305 TPI and 5 speed and these were my results.

 

I went form 3.42's to 3.73's in my T-5 305 TBI. Chopped about 4/10's off 1/4 mile on the accelerometer and still cruises on the highway without killing the motor. Go with 3.73's if you are not driving long distances at high speeds often. You will be amazed at the difference with the new setup.

 

i smell bs here........ Sounds like driver error to me.

Anyways i'd go 3.43s because, these engines don't make any power up high.... No reason to rev the crap out of them, al you do is increase wear and lessen gas milage.

 

Hey, before you make a bad assumption, consider the fact that not everyone here is running a stock motor that makes no top-end power. Driver-error... my accelerometer hasn't lied yet... you *****.

 

well being that your not running a stock motor it's pretty tough to give someone the opinion that those gears would be that big of a gain then....

Btw i know i'm a ***** thanks for enlightening those that didnt .

All i know is 2.73s suck *** and are no fun around town. Gearing it up should be a nice sotp difference no matter what.

 

Looks like we can agree that he needs to step up to a shorter set of gears. I just know that after running the stock 3.42's for a long time, those 3.73's gave my Camaro a kick in the a--. I mean, why not go with 3.73's (if you are not on the highway all the time)? You expose the low end torque that these F-bodies thrive on, and the fact that we lack top end does not matter if you are ripping through the gears faster. Two identical Camaro's where the only difference is the gearing... one has 3.42's and the other 3.73's. Holding the drivers' abilities constant, who is going to win a street race? My money is on the 3.73's.

 

i suppose the 3.73s may win. At a track situation going with tall gears is pretty tough on you with a 700r4 though. That super low 1st gear kinda turns tires in to mush it seems .

Although in a street race about all the further you seem to geti s to the next light so taller *numerical* gears probably would win.

 

Many great idea's guys, lots of opinions and pros and cons of each....i am leaning to 3.73 based on one reason...little to highway driving, and very little above 75 MPH, i'm old ya know LOL!

how old? well I bought my Camaro new, and its a 1991

 

Stock heads, cam, and TPI ='s 3.42 whether you drive on the highway or not.

 

Totally agree, I have been road racing a third gen for almost five years. TPI guys all have 3.42s. I run a carb, I run 3.73s, that works best with that motor (L69).

 

TPI makes alot of its power down low. So you want to take advantage of the torque that the tpi makes, and keep it in its powerband. Thats why 3.42's are a better choice.

 

ack!

My heart says 3.73, but it seems common sense for TPI according to you guys is 3.43
**** I don't want to make the wrong choice!

 

Did you calibrate after you changed the gears? If not it would read faster.

 

Ive seen a few tpi cars with 3.73's shift into OD before the end of the 1/4. Now we dont want that

 

with 3.73's on my auto twin turbo, I topped out at 109mph at 6000rpm. Stock 700r4's don't shift into overdrive unless you let of the gas to 2/3.

I'm going with 3.23's, but I vote 3.42 for you.

 

What would be better gears for the LO3...3.23s or 3.42s??? Reason i ask is because the LO3 makes all its torque at 2400 RPM and its HP at 4200(?) i think.

 

Sure did. With each modification that requires recalibration, I have recalibrated the accelerometer, right down to weight changes. I am lucky enough to have a free scale here on the base that I have access to 24hrs-7 days.

 

I'll have to look into it. Maybe the early ones did or something.