I currently have a 92 Camaro RS that has an open 2.73 ratio rearend in it. I have a neighbor that has a 90 IROC that has a posi limited slip 2.73 ratio rear in it. He is parting the car out and wanted to know if I wanted the rear that is in it. Is there a difference in the 2 rears that I would need to be concerned with? I was considering just taking the carrier and dropping it in mine seeing as they are the same ratio, I shouldn't have to change the pinion gear, so the backlash is already set. My car has about 60,000 miles less than his too. Is there a difference in the splines on the axle? I know there are 26 and 28 spline axles out there, so are these cars different or should I take the axles too? Need help. Also, if there is anyone out there looking for 90 IROC parts, let me know and I'll tell him. the only things I have taken are the hood, and the drivers window motor. Everything else is available, other than the rearend.

 

Hope he has a good reason for parting the 90' IROC

The rear end is a direct swap. If it has disk brakes, take his prop valve and e-brake cables too. If not, it's plug and play.

 

Would it be easier to just take the carrier out instead of the entire rearend? I don't know if it has disc brakes or not.

 

While I have never done a carrier swap, I highly highly doubt it would be easier. I'm not sure if your statement about not needing to reset the gears to spec is accurate, and even if you're right about that the rear ends are cake to swap out.

 

No. If the donor has disc brakes, the swap would be beneficial if for no other reason than the car is equipped with 11.7" rotors and single piston alum calipers. Limited slip with high gears seem somewhat worthless, IMO.

JamesC

 

So is limited slip positraction and posi different? If I swap these out I will at least have a posi in the car and if I want to go to bigger gears than I can. The way it is now, all I have is an open rearend.

 

just swap the rear end. wont take you long. as stated above, if the rear has disc brakes installed take the proportioning valve out of the car as well.

 

Same.

Swapping the entire rear ends is much easier than swapping carriers (and all the potential hassles of having to shim it). Besides you have to swap both ring and pinion as they should swap as a set. Unfortunately both are a 2-series carrier, so the highest ratio that will fit is 3.08. Not much better than the 2.73 you already have.

I don't know your ultimate goal, but I wouldn't do the swap unless the rear end was free. If it were me, I'd keep looking for a 3.23 or 3.42 (10-bolt) or 3.27 or 3.45 (9-bolt) ratio rear end to justify the labor in doing the swap. It's a good time to drop the gas tank and pop in a new fuel pump and filter while you're at it.

Lon

 

I almost agree with this, however given the price of a pump and the extra labor involved (chopping exhaust?) I would say it's best to take note of what's involved in dropping the rear end and think about what would make it easier so down the road when maybe you do have to change the fuel pump dropping the rear will be easier and faster and make the job less daunting.

 

You don't have to chop the exhaust to replace the pump. At least I didn't have to.

 

The 2 series posi unit, which will be in that rear end, is NOT a performance unit. That, along with the fact that you're not improving your ratio, makes the swap hardly worth the effort. UNLESS you're upgrading to a PBR disc rear-you didn't say.

Even the 3 series posi units with the stronger springs are questionable after years of use. Those 2 series units have clutch springs that belong in a ball point pen. A comparison photo is included in this post:

https://www.thirdgen.org/forums/tran...=series+posi+2

 

its ultimately up to you to do the swap. its all bolts so its not that hard, just be careful not to bend the brake lines while doing so. but it would be who of you to find another rear end out there like lonsal said. i waited and found a nice 9 bolt with disc's, posi and 3.45 gears and swapped the open drum 3.08 so it was a nice upgrade. never did the prop valve works fine for now but i will do it in the future soon. i dont think a whole rear end is worth it just for PBR brakes, same **** just another type of metal