I will check to make sure before making any purchases but given my research I believe I have 2.73 gears (no clue if it's Posi or not), and 28 spline since I have a 91 firebird. I also believe it has drum brakes, but I'm really not sure...any info on that subject would be great (if they only came with one option or something).

My question is will these parts work to swap the 2.73 to 3.42 gears using my current set up regardless of brake/posi or not?

SummitRacing.com
Ring & Pinion Set Part #: G875342X $189.95
Free Chrome Diff Cover Part #: 730302 (free for buying the gears)
Ring & Pinion Install Kit Part #: 3001K $109.95

Stupid question but, do I need the install kit? Is there anything else I need to do the swap thats not listed?

Yeah I don't know anything about the axle more than what I've read on this site so forgive me if I sound a bit ignorant on the subject...well bcuz I am, lol. ^_^

Thanks in Advance.

 

Yes you ABSOLUTELY NEED the kit.

To put 3.42 gears on a 2 series carrier, you need the "special" "thick" gears, a spacer, or a 3 series carrier. If the gears you didn't link to are that kind, then they will work.

Skip the "free" "chrome" cover. ebay it or something. Get one of this type instead, if you do ANYTHING at all. http://www.taperformance.com/products.asp?cat=48

Gear installation is not something for the inexperienced. It requires specialized tools the average hot-rodder doesn't generally have. If you don't know what kind of brakes you have, or how to tell, that's a pretty reliable indication this project might be beyond you. Read a few of the posts on this forum about gear changes before tackling this. Not saying "you can't" do it, or anything like that; only, you won't have a very high probability of success. Better would be to find someone in your area that does these, and pay them to do it, while you watch; then you'll be better prepared to do the next set.

Do a brief search on my userID and the words "crush sleeve eliminator" (I always tell people to get those, so that'll pull up A BUNCH of posts about this) to learn more.

 

Another thing to look at is just swapping for a used rearend with the gears you want.

 

Ok I figured you needed the kit, it's just always sold seperatly or as an option (like you don't have to purchase it) so it just confused me a bit.

Those gears are for a 2 series carrier: "Designed to fit 3.08 and numerically lower carrier"

I just don't want to go "used" since I really don't know what I'm getting. It would probably be fine, I've just had to many not great experiences myself so I don't want to push my luck.

I think I know how to figure out what I need, but where do I get what I need for the speedo to read correctly?

 

The answer to THAT question is in all those other posts, too. A bunch of us, myself included, have posted that DOZENS of times. You probably don't even have to go to the "next" page on this forum to get to one.

If they say they're for a 2 series carrier, then they'll fit your carrier. Next time post a link instead of some words and maybe we'll go look at them for you, which we WON'T if we have to do all the work FOR YOU.

Do a little research and reading on your own. Those of us who typically try to help people out, are only willing to do just so much spoon-feeding. We only help those who help themselves.

 

I HAVE searched the forums and have read/bookmarked many useful pages, I've even got a link to a place for the speedo gears but I'm just not positive what I need, and I like to double and triple check before I shell out around $400 (not mentioning labor).

I WOULD have provided links but whenever you link to the page on summit it redirects you to the front page anyways. I'm not an idiot. Thats why I provide the site link summitracing.com and provided the part numbers.

I understand you don't like to constantly anwser the same questions, but if thats the case then you need not respond at all "if you have nothing nice to say", well you know how it ends.

Thanks to anyone/everyone else willing to actually provide me with a conformation since I did my research finding what I thought were the correct parts.

Again if anyone has any info on the speedo gears that would be great because I'm going to be getting some 18in rims so I don't know how to figure out what tire diameter will go with that to make the speedo read correctly??? Thanks.

 

No, it doesn't. As an example: http://www.summitracing.com/parts/RAT-4111/ Not so tough, eh?? I made it easy on you by merely copying and pasting, that's all I ask, is that you do the same for the rest of us.

Speedo gears are on the order of $10 apiece. No need to worry about $400 for that.

You don't pick tire dia to make your speedo read right. You pick tire dia to get the various tire properties you want. On my car with 18" rears, I have the stock C5 size, whatever that is... something around 345/45-18 but I could easily be wrong. You'll no doubt end up with a similar size because that's what fits in the wheel wells.

Once you have your ACTUAL (not "calculated" from the "trade" size, but instead, MEASURED from the ground to the center of the wheel with the car sitting there normally) you "calculate" the speedo gears you need based on the 1000 turns per mile constant that I and others have posted on here DOZENS of times, and go to the "speedometer world" link I posted just a couple of days ago - probably still on the front page of this forum - and buy the gears you need. Since you're starting out with a low-end car with the 2 series gears, you'll probably have to buy the housing as well. The link that I and others have posted repeatedly contains that too so no problem there.

You're right, I don't like to constantly answer the same questions over and over and over; please do those of us who are WILLING TO HELP OUT, the favor of reading the first couple of pages of posts, because every single thing you have asked IS ALREADY SITTING THERE.

 

It's whatever, I've found what I need already, I'm sorry I wanted to verify the information, you really don't have to be so rude. It redirects me for some reason on summit, and I meant $400 give or take for the install kit, gears, speedo gears, and shipping.

NEVERMIND, sorry for asking a question to verify the information I got FROM READING ON THIS SITE. I guess some people have nothing better to do than put others down.

 

When someone says they want to do a rear end upgrade with new parts I will some times post this just to give them a idea of what it can cost and the parts and pieces.Some you need and some are just suggestions,for primarily street/strip use .I recommend the Eaton posi. and L.P.W. support cover. If you already have the 28 spline axles than subtract $250.00 from my total. This is my upgrade =

https://www.thirdgen.org/forums/tran...de-photos.html
Master bearing kit = $90.00
Axle bearing and seals = $30.00
28 spline Eaton posi = $535.00
28 spline Axles = $250.00
L.P.W. Ultimate cover $160.00
Ring and pinion = $150.00
Install = $300.00
You should not need the 28 spline axles.

 

Thanks! I hadn't found your post in my search. I really appreciate the help.

 

I understand that you might be worried about going used, but

You would be able to buy 3 used rearends (which you could easily install yourself) for the price you will be spending to upgrade yours.

Especially if you dont plan on getting a new posi unit if yours is in fact open. But it is your car and your money.

 

I guess that's a good point. My dads just been working on cars for like 30 years and since he's the one that mainly puts the goodies in my car, well, it's harder to get him to go along with something used like that... ultimately its my choice but you get my point. Might just have to fight him on this one...perhaps I can get the 3.23's out of my wrecked v6???? Would that still be a significant difference from the 2.73's?

 

yah dude, just get the 3.23s from your wrecked V6. Those would be great for your car.

 

Is the V-6 a L.S.D. ? and if it is, what type/name of carrier is it ?

 

i took the cheap way out.i swapped in a 3.42 from a v6 camaro .they are mostly all 3.42s and are the same strength as the v8 rearends.

 

DONT ATTEMPT ANYTHING BEFORE PICKING UP A HANES MANUAL AND LEARN EVERTHING AOBUT YOUR CAR

 

Id get a 90-92(better 28 sline axles) v6 rear end. Those have the bigger v-6 engine so they put 3.23 gears in them. The lower 3.42s found in 82-89 v-6 only have the 26 spline axles.

Ya it kinda sucks you have to choose either a lower gear or a stronger axle. Wish they would have kept the 3.42 ratio in 90-92 cars. Put a mini spool in it if you want posi. just be careful in the rain. the rear will kick out in a hurry when your not expecting it.

 

If it was me,and a few years ago it was. My first priority would be making sure I ended up with a L.S.D. ,one that has a great reputation as a strong/dependable/street/strip friendly unit. I don't feel that the units that came with so many cars that G.M. built fit that description. Unfortunately that pretty much leaves out a used rear end unless your going to pull the gears and drop in a new carrier. Thats why I ended up with the rear end I have. In order to make the 10 bolt I built fit those qualifications I chose the Eaton posi. With that and the L.P.W. Ultimate cover it turned out to be one of the stronger rears available with the 10 bolt.
By the way ,IMO spools are made for ¼ mile cars. Running one on a street car is not suggested.

 

How long do you plan on running with the rearend and how much power do you see yourself trying to put through it in the future?

I agree with Ron's route if you plan on running the car for a long time and dont plan on seriously increasing the power.

It is all going to depend on your budget and intent.

I also completely disagree with a spool for any street use.

 

I'm going to purchase the 3.23 rear end off my old 91 tomorrow with the stuff to make the speedo read correctly. (My dad will be switching the rear end, and yes he knows what he is doing ^_^).

It's just going to be on the street, no intent on racing, but I want a nice set up and the ability to kick *** if the situation so arises (at least I'll be better off than with the 2.73's).

I will find out tomorrow but is it possible the v6 3.23 axle has disc brakes instead of drum brakes? I hope so.

 

Posi.? or No Posi. ?

 

No posi, I figure I will change it over later, working on wheels and tires, and paint...I only have so much money...unfortunately, lol. I just don't feel good with buying used other than the one that was on my old car. Paranoid I know, but I've had to much crap with this car to not be a little superstitious.

 

OK, so I have them pulling the 3.23 rear end, but assuming both cars (91's) have an electronic speedo how do I get the speedo to read correctly. I just thought I needed to get the drive/driven gears off the same car with the rear axle, but the guy is telling me I need to change a chip in the electronic speedo, and not the drive/driven gears??? Is this true?

 

Yes,I know how it is.Short on cash. Your going to have fun with your new gears but the higher the ratio the more prone you are to have wheel spin especial with a open differential. Its called a "one wheel peal."Any way sounds like you car is moving along nicely and I cant wait to see some photos of your progress. Keep up the good work.

 

thats absolutely false.

 

323 is a good choice, i went with 342 but sometimes feel like its a little too much

 

ok, if that's false then what do I need to do for the speedometer to read correctly (or really close).

Tire size: 265/35/18 (25.3 height)
Transmission: 700r4
Changing to: 3.23 open
Current driven/drive: 41:15

When I did the calculations from this sticky I get 38.6 if using a 15 drive gear for the calculation (so 38): https://www.thirdgen.org/forums/tran...eedometer.html

If I use a 38 driven gear isn't there something else I have to change since there's a 41:15 in there right now?

If I change the 15 to 17 in the calculation I get just under 44 (43.78). Which they say exists, so can I do a 44:17? will that work without having to change anything else?

Do I have to change the VSS (electronic speedo thing)?

Thanks.

Update: I looked on this site (http://www.transmissioncenter.net/sp...__va.htm#700r4 gear driven) and they have the 17 drive gear but it says they are out of stock on the 44 driven. Where else can I purchase this?

Also if i look under 700r4 driven electric is says there is no 44 (do they mean out of stock here as well?)