Hello all .. i honestly didn't know where to post this so i thought it would go here .. i am interested in 3.73 gears .. i have a 1991 305 v-8 firebird auto.. i also heard that it has a dissapointing 170Hp .. i havn't done alot to it besides the K&N filter and getting my cats removed .. also i have 5 inch crome tips but thats not adding to performance .. I was just wondering if 3.73 gears really would make a big differance .. if so how much would that run my as far as installation .. and just getting it .. thanx to anyone that could help

 

3:73 gears for your set up will not help for your street car. I would try to increase the Horsepower & Torque By adding Headers and Catback exhaust for starters. Also get rid of those tin can exhaust tips. My opinion

 

i agree, get the motor breathin, get all the free tbi mods done. then look into a gear change. what did the car come with? 3.08? thats what my 89rs had. but it was 5 speed. i really never did any real mods to mine, i just saved up for a 350 tpi car.

 

alright thanx alot for the help .. i honestly don't know what gears it came with .. i just ordered the ram air hood so hopfully that will be good ... also i am saving up for the 350 engine .. i really wanna find a firehawk engine to put in mine but i can't find one .. but anyways thanx for ya'll helping me out

 

I went from 3:23's to 3:73's and never looked back. The gears are a perfect match for my combination since I have a manual trans. I let one of my friends drive mine after he put my old rear in his car with a TH350 and he couldn't believe the difference, his next planned mod is 3:73's.

If you do alot of highway driving at speeds above 80 mph you don't want them though. If it's just around town use and occasional racing I'd swap the gears in heartbeat. It comes down to how you use the car and what you want from it.

 

Again, better Mods for a stock car then changing the rear gearing.

 

That would be too much gear for that motor as it sits. 3.23 or 3.42 would be better choices.

It came with 2.73s.

 

Changing the rear end gears basically gets you a better launch from a standing start (but 0hp gain). If you really want to improve 1/4 mile times, listen to these guys. Headers & exhaust should come first - get your engine breathing, one of the most noticeable hp gains. Good gears are expensive, and tough to put in for someone with little or no experience. Do you have a TBI or TPI engine? The TPI engine has a factory rating of 220hp. The Firehawk engine is basically a modded GM 350. If you can get a guy to mod a 350 or get a pre-modded crate 350, that's the way to go. And if you want some REAL performance (at a price), go with a professionally built 383. Just my two cents.

 

Im just throwing in ( to no one in particular ) that gearing (in tranny OR rear) is one of the most important aspects of how your car launches and drives. without proper gearing your car will either shoot out of its powerband (and slow you down) or not get into its powerband (and slow you down) so its very important to match what you have with what you need.

 

yes & no....but you will pick up some time in you E/T....but most likly loose some gas mileage.

~Nate~

 

Generally speaking, the higher the engine "wants" to rev, the lower you can go with the gearing (higher number). With a typical TPI unit gasping for air by 5K, 3.73's will get you out of the powerband too fast, kind of like when you were a kid and tried to go real fast on your bike in 1st gear and your feet came flying off the pedals. 3.42's are great all around gears but unless you start modding the engine I wouldn't go with 3.73's. Now if you get it to rev into the 6K+ area, go for it!

 

With a 5 speed, the 3.73's are the maximum gears you should have for driving on the freeway. Your RPM's will be much higher in your overdrive 5th gear, as opposed to your stock 2.73's. However, 3.73's are about the highest gears you can go if used on the freeway. I believe the z06 use 3.55's, and there freeway demons, however, there runnin T56-6 speeds as well. If your a third gen T5 manual owner, the 3.73's are a good choice for street and freeway, however, your RPMs will probably be about 1000 higher than what your stock provide while cruisining freeways. Not to mention, that awesome torque you get out of the whole. It is night and day between the stock 2.73's and the 3.73's

My friend has 4.10s on his stang, and he basically has to use the slow lane on the freeway with that ****. Then again, its not a commuter car.

3.73's are pretty good in all aspects though.