hahah, obviously, LOL

 

Most of the V8 cars came with 245/50R16 which is a 25.6" tall tire.

My car has stock 2.73s. They shattered on me a few days after I got back from the dragstrip where I only ran three 2.2x 60's with my stock 305/auto. Replaced with an LS1 rear, expecting a 3.23 ratio and found it to be a 2.73 ratio again

Anyways, now I have a set of 3.42s sitting in my garage with 18k miles on them waiting to go on my car. It'll be a nice match with the RPM-loving LT1 intake that's going on my car sometime in the next few months. I'm planning on making power to just under 6k. The stock 2.73s would suck for that kind of powerband.

 

I don't know about the 9 bolt BW, but the 10 bolt GM rear uses different series carriers for the 2.73, 3.08 vs. 3.23 and up. Didn't see it mentioned, so I thought I'd bring it up. Do the BW rears use different carriers too? If you're going racing, don't waste $700 on factory gears. Save some more and go with a 9" or a 12 bolt. I'm doing fine with my junkyard 10 bolt with SLP posi, but I don't race the car either.

 

I had a V6 bird right before I bought my camaro, and whenever I did burnouts it was 1 mark, are you sure they all came with 3.42?

 

they are 3.42's the reason you only left 1 tire mark was because you have no posi

 

Well some came with 3.23's but there were only 2 options 3.42's or 3.23's. I have seen mixed transmissions with either ratio so you cant assume because its an auto it has 3.42's or vise versa.

 

Alright so the gearing has nothing to do with weather or not a car has posi?

 

mm yea pretty much... the number is just a gear size. could be any size and be posi or open. correct me if im wrong but im pretty sure thats how it goes

 

That's how it goes And I'm pretty sure 9bolts have different carriers as well (i.e. a 2-series and 3-series).

 

9bolt BW's also have different series carriers. For 3:27 and up they are the larger series 3 carrier. As with 10 bolt, all of the gear ratios are stamped on the ring and pinions. At one time there was a spacer kit to allow series three r&p's to be used in the series two carriers - these are now as rare as chickens teeth, and now days it's easier to just replace the whole carrier. Cocacolakidd

 

It should actually be 3.08 and higher for the 9-bolt. It is a PITA to find 3.42 of 3.45 gears for the 9-bolt. My car was stock with 3.45. It worked well with the LB9 305.
FBird

 

I didn't think there was ever a 3.08 ratio made for the 9bolt. I thought it was only 2.77, 3.27, 3.45, and 3.70.

 

3.08 isn't found very often. Kinda like a open drum 9 bolt.

 

So I was contemplating changing the ration when I got this new rear end out of a 97 camaro (wanted the discs brakes). I am currently running 3.42's with auburn posi. THe motor is a 383 with a holley stealth ram and pulls well into 6000rpm (although I am still scared I built the motor). I have a t56 from a 96 camaro, any suggestions? Would 4.10 be too high? It is more of a weekend sunny day driver. Only goes to work on Fridays. Suggestions???

 

3.08 came in all of the base-model 5spd V8 cars, i.e. L03/T-5 combos in Firebirds and RS's. Rarely was it posi though.

 

Readabout half of the post, but just wanted to say that personally i would reccomend a 3.42 since I have a 3.27 stock, and I thing thats a bit too low. What I mean with that is when cruising athighwayspeed (about 55-60) the revs are so low that it gotta give away some accelleration. I thought it was a 2.73, but I looked up the VIN, and it said 3.23

At least I cansay thet you wont experiance "to high revs" with a 3.23, most people riding with me are baffled about how low the cruise rpm is, myself included.

 

Does anybody have 3.45 gears for a 9 bolt they are looking to sell?

 

I have a set you can buy. They are trashed though

JK. Good luck finding those. You are better off looking for 3.42 or 3.23. That is still going to be like striking gold.

 

I know! My iroc came stock with 3.45 but I blew the pinion, currently running 3.27.

 

Since I destroyed mine and can't find anything to replace them with, I'm going to replace the whole thing. I have a 4th gen rear in my garage right now. I just have to work out the brakes and it is going in. I got the whole rear minus the brakes pretty cheap. Actually it was cheaper than getting a new set of gears for the 9-bolt. Not having to find the needle is worth the extra $ to me.

 

dmd91rs--about 4.10's with a T56: jmd has advised me that 3.90's are excellent behind my T56 in an 1800 lb. car and he really knows his T56 stuff. The car has an 8.75" Chrysler rear so the choice is between 3.91 and 4.10.
Last year, Chevy High Performance said that a T56 behind a carbed engine with a mid-range cam needs 4.10's for the street--and I think the T56 has sort of a tall first gear to work well with that ratio. In a Camaro convertible, carbed and a T56, I think I'd go with 4.10 posi's.

 

rbjones- appreciate the input. It is fuel injection but really should not matter. Plus I look at the 6th gear overdrive as plenty to compensate for the 4.10 on the highway. Most other times I just look for mustangs to embarass!

 

Ok, excellent--that "Holley Stealth Ram" confused me. I'm familiar with the Weiand Stealth intake. If you've got tuneable EFI the taller gear would work great, too, but I grew up in Socal and understand the need to tromp Mustangs--thus the 4.10's.

 

are the stock 9 bolts any good? are they better than the 10 bolts? are they worth building up?

 

Yes the 9-bolts are stronger than 10 bolts. If you have the money, it is worth building them.

 

OK guys help me choose the best all around gear for my combo!

327 engine with a single pattern cam 292 dur .480 lift (before 1.6 rockers) 2600 stall convertor and a HSR intake.
What gear would be best suited for my car?

 

can someone post a link for a 3.42 posi? Ive been looking every and cant seem to find any.

 

Check this post out:
https://www.thirdgen.org/techbb2/sho...hreadid=239666

I just went through the gear swap from 3.23 to 3.70's. My motor spins to 6400 and the 3.23's made the shift from first at 56-58mph. After installing the 3.70's it holds to approx 38mph (WOT of course). The change was definitely needed in my case and made a world of difference! I've got my 3.23's boxed up ready to sell, just havent posted it yet. If youre interested let me know.

 

What sort of time are you running with your 8???

Just asking casue I know guys with 2:90 and 3:08 that still run 13s in 3500lbs cars

gears can help but there is no replacement for torque.