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So I was looking into getting this for my car. Currently I have a 10 Bolt with 2.77s and Posi. I think 3.42 would be about perfect for what I want (A bit faster, but still drivable long range) but does anyone have any experience with this particular set and were they good quality?
OTOH, if you have a 10-bolt, you don't have 2.77 gears now; and if you have 2.77, you don't have a 10-bolt. You're FAR more likely to have a 9-bolt anyway, given what car you have. In which case of course, those gears won't fit. Count carefully before ordering.
IMO 3.42 is on the absolute outside edge of what works well with a stock L98. You may well find yourself with one of those deals where it'll break your neck leaving a stop light, but you won't be able to pass a semi on a 55mph 2-lane road.
OTOH, if you have a 10-bolt, you don't have 2.77 gears now; and if you have 2.77, you don't have a 10-bolt. You're FAR more likely to have a 9-bolt anyway, given what car you have. In which case of course, those gears won't fit. Count carefully before ordering.
IMO 3.42 is on the absolute outside edge of what works well with a stock L98. You may well find yourself with one of those deals where it'll break your neck leaving a stop light, but you won't be able to pass a semi on a 55mph 2-lane road.
I had it on stands and it's a 10 bolt. The Code Says it's a 2.77 and it lopes along at like... 1500 RPM at 65 MPH on Stock tires. Hell, I dint even put it in OD driving around town.
If your "codes" say it's a 277, but there's a 10-bolt in the car now, then the rear is NOT the original one. PERIOD. All talk about "codes" is a TOTAL WASTE OF TIME at that point. You will have to pop the cover off and LOOK AT IT to see what it REALLY is. Because NO MATTER WHAT ratio it is, it is NOT what the "codes" say.
For that matter, you might find that it already has 3.42s in it. You won't know until you look. Buying parts for something you don't know what it is, is a SUREFIRE 100% IRONCLAD GUARANTEED WAY of having to pay 2-way freight and restocking charges and such as that.
It look like the stock axle to me, it's got 10 bolts on the cover and the code GH3.. the RPM's seem to match up. I have never heard that these cars didn't have 10 bolt rear ends stock.
Can I bug you for your information as to were you are getting your Axle Data for these cars?
I don't bother with "axle data". It's too unreliable.
All I can tell you is, WHAT THE PARTS ARE. And that includes, that if your "codes" say your rear is supposed to be a 2.77, but there's a 10-bolt in your car, then it's not original. 2.77 is a 9-bolt ratio and does not exist for the 10-bolt. There IS a 2.73 for a 10-bolt but I haven't the foggiest dimmest remotest faintest hint of a whiff of a glimpse of a clue what any of the "codes" for any of it is.
And yes, the 10-bolt was the more common rear in these cars, but the higher-performance ones starting with certain Firebird variants in 85 and then Camaro ones starting in 87, up until 89, got the 9-bolt. Your car is among those that would virtually certainly have come with a 9-bolt, which of course explains why the "codes" call for a 9-bolt ratio. 2.77 was the base-model L98 ratio, while 3.27 (also not available in the 10-bolt) was the top optional one.
Look inside it and see what you've got before you order anything, since what you have is NOT anymore what your "codes" say it is. The 2.77 9-bolt that came in it is no longer there. SOMETHING ELSE, yet to be determined beyond that it's a 10-bolt, is in its place.
Incidentally, when you pop the cover off and look, take some good photos of what you find; particularly, show a good view inside the "window" of the carrier. Since it's been swapped, who knows whether it's still a posi. All, or nearly all, 9-bolts were posi, but not many 10-bolts had it. It would be good to make sure of that as well before spending money on something that isn't worth it or that needs other things to realize the full potential of the project.
By your description, it's probably a 2.73 10-bolt, but "probably" won't make parts fit.
Does it have disc, or drum, brakes? If disc, are the calipers cast-iron (rusty), or aluminum (they have fins)?
First off, thanks Sofakingdom for your input! I put her back up and jack stands only to find out I was counting a lump of road grime *sheesh*. I slapped her back on Stands,crawled under and rubbed my finger around it and, lo and behold....
You were 100% right. She is a 9 Bolt rear end. It has the little Posi Tag (However with the twin streaks of black I have left I am not shocked), I also put it in neutral and spun the tire on the drivers side and the passenger side spun in the same direction. 2.73 ratio makes the most sense with how low my RPM's are at 65, but I'll look just the same (I may have a shop do this work though as I have only set one ring and pinion ad did in wildly incorrectly) .
I also shot you a picture of my Breaks, looks to be aluminum calipers.
The 9 bolt will have the 2.77 gear, which means you have a 2 series Borg Warner limited slip differential. If you install a 3.45 then you will have to get a 3 series differential. There is a Truetrac available for the 9 bolt and it would be a better choice over the Borg Warner.
You have a much better rear than the 10 bolt. I shattered my 10 bolt in my last car the first time at the strip on drag radials. I went back with a 9 bolt and 3.27s and it held up fine no more problems. Id love to come across another one.
So the 3.27 fell through once it was discovered that there were some bad teeth :-(
So is 9bolt.com my only option to get something other than a 3.70? Cause that ships from Oz lol
Originally Posted by sofakingdom
Don't forget, if you have 2.77 now, you'll need not only the gears, but also a 3 series carrier, to change to 3.27.
Werd!
Originally Posted by dmccain
You have a much better rear than the 10 bolt. I shattered my 10 bolt in my last car the first time at the strip on drag radials. I went back with a 9 bolt and 3.27s and it held up fine no more problems. Id love to come across another one.
I keep reading that the 9 bolt/7.75" is a decent rear end, but since it was in limited production parts are scarce.
I would think that you should be able to find a good used 3.27 complete rear or a 3.23 or 3.42 rear 10 bolt easy enough complete, I build rear ends and I built a 91 Camaro 10 bolt for my 87 T/A with a torsen out of 99-02 Camaro/firebird did it all for around $200 if you shop right at U-pull it type yards you could go and see what you could get all parts at once - gears carrier housing and axles put all in housing one price - usually around 100 bucks.
either 9 bolts or factory 3rd gen 10 bolts use auburn type posi's and they do wear out, then they're pretty much junk. the Torsen dont have that issue is why I built mine that way Used 3.23 and 3.42 and 3.73 are common ratios in S10 blazers
I would think that you should be able to find a good used 3.27 complete rear or a 3.23 or 3.42 rear 10 bolt easy enough complete, I build rear ends and I built a 91 Camaro 10 bolt for my 87 T/A with a torsen out of 99-02 Camaro/firebird did it all for around $200 if you shop right at U-pull it type yards you could go and see what you could get all parts at once - gears carrier housing and axles put all in housing one price - usually around 100 bucks.
either 9 bolts or factory 3rd gen 10 bolts use auburn type posi's and they do wear out, then they're pretty much junk. the Torsen dont have that issue is why I built mine that way Used 3.23 and 3.42 and 3.73 are common ratios in S10 blazers
But, mine is actually a 9 Bolt...
Which the only gears anyone seems to make for them is either 3.70 or 4.10s. I would love something in the 3.20 or 3.40 range.
Which the only gears anyone seems to make for them is either 3.70 or 4.10's. I would love something in the 3.20 or 3.40 range.
3.27 is a pretty common 9 bolt ratio I'm not a big 9 bolt fan- poor parts availability when posi cones are worn good luck finding them - same with 10 bolt auburn's but IMO they're more available and they can be replaced with Torsen's if you have 28 spl axles
You can get a Torsen for the 9 bolt, and the 3.70 gears everyone sells are all from the same factory so buy the cheapest set you can find - probable Motive. They work fine, but will whine a bit. The 9 bolt is a strong rear end, with factory 28 spline axles, and for racing it requires no C clip elimination, etc. I like mine and already had it so it was an easy choice.
01-31-2019, 11:51 PM
