I'm looking for taller gears than my stock 2.77s. My options are getting new gears and a series 3 carrier for my 9 bolt and install it myself. Or I can swap in 4th gen rear end. I don't mind swapping the rear end, the wider stance doesn't bother me, and upgraded brakes I guess isn't bad. My main question is which is going to be cheaper once all materials are added in. What should I expect to pay for gears, a 4th gen rear, carrier, etc. Thanks so much!

Same boat here. I just started thinking about a 4th gen rear so I haven't received the information on what the cost difference will be going that route.

Here are the options I have been considering:

1.) New rear differential with 3.23, posi, disks from '86 Z28.
2.) Replace the internals of my current diff with posi, 3.23.
3.) NEW - Find a 4th gen rear for replacement.

It's looking like option 1 is the most cost effective. The best part of that is the brake upgrade to disks (currently have drums). The added cost there is the proportioning valve for the drum/disk conversion which is rumored to cost around $100. The new rear axle and differential with brakes is gonna cost me around $250.

I'm curious about what the 4th gen rears run used...

4th gen rears are like $250. I'm curious what else I'd need other than a carrier and gears. How much does a carrier even cost? I mean, gears aren't exactly cheap so it's adding up quickly.

Yeah this is a tough one because it'll depend on how you source the parts for the 9 bolt. There are deals that come along every once in a while. Recently there was a deal on 3.7x gears for the 9 bolt, under $200. And if you can do your own rearend work thats another plus. Its not impossible to find good prices for 9 bolt parts and beef it up. Its just hard to do. Generally speaking the 9 bolt stuff is more expensive, just look at www.9bolt.com its insane. If you need that 3.4x gear and nothing higher, the 4th gen rear does make alot of sense since alot of them came with that ratio OEM and can be found in the yard.

I got my rearend out of a '01 4th gen, with 3.73's, posi and disk brakes for 300 bucks. I would think it would be cheaper to get a 4th gen rearend cause you can't put posi, 3.73's and disk brakes in a thirdgen rearend for 300 bucks. Plus you can run 4th gen wheels and only have to get spacers for up front.

i have a set of 3.27 gears out of an 9 bolt. pm me if interested.
thanks

When considering this swap, keep in mind that the old delco moraine discs rattle like a ****..... I've had two cars with these and would take a drum rear any day over those. If your patient (and lucky) you can still find some 90-92 disc rear ends.

So just swaping in 3.27's 9-bolt gears should be a piece of cake if you already have a 9-bolt am I right? Its more expensive switching out a 9 bolt for a 10 bolt right.

first, if you dont already have one, get a good converter... like 2800stall or so. really wakes up the car. my 2.77 L98 with only headers/catback/gutted airbox went 13.89 at 97 on street tires with 2800stall

if you got 2.77's you need the 3.27 carrier to swap in the 3.27 gears.. i got one on Ebay for 70 bucks and put it in and after about 2000 hard miles on it, i think its failing.

it could be partly due to the rear end fluid.. it might have posi additive to it which isnt good as the posi is a cone type and the additive stuff will just make it slip..... cuz the last burn out i tryed to do the day before i put it away for the winter it only peeled one wheel while the other one stayed planted or barely spun.

so its a risk trying to buy used.... unless your absolutely sure of the posi's condition if its a extremely low mileage unit. else you never know how long its gonna last.

figure it this way.... i spent 70 on the posi carrier and like 50-60 on the ring pinion for the 3.27 swap. i spent 120 on the install kit with bearings/etc. then i spent 150 to have it put in. thats about 400 bucks for a used posi setup.

i bought a complete low mileage 4th gen 10 bolt rear with 3.42's and the larger disk brakes for 300. i would have been better off to do that in the beginning.

Why did GM even put 2.77's in a performance car. Ford did the same thing with the mustang GTs too only they used 2.73's. Soooooooooooooooooooooo dumb

well for one it helped keep gas mileage...

2.77's are good with the OD auto trans. they keep rpms down. but the 700r4 has a deep first gear ratio... 3.06. so that helps keep some performance too even with 2.77's. first gear in my car was always a blast! didnt last very long but it was fun, and even quicker with 3.27's

Hey Orr89RocZ what kind of stall should I get for my car. Cant find anything and I thought you would know...thanks