Is this possible or not? I have an 89 camaro with 2.73 non posi and have no idea what rear i have, 7.5" or 7.625? 26 or 28 spline? I found a nice 9 bolt and am wondering if it is possible to swap that in from my 10 bolt? What do you guys think i should do for a new rear end? Thanks

 

9 and 10 bolts interchange from 3rd gen f bodys

 

I stuck an '85 3.70 posi/disc 9-bolt in my '91 RS (came with a 2.73 peg-leg 10-bolt.) It's an easy afternoon swap.....everything bolts right in.

 

Would swapping over from 26 to 28 or 28 to 26 spline matter when doing a whole rear end swap? Im looking at this rear end

http://cgi.ebay.com/ebaymotors/ws/eB...category=33731

 

The spline count didn't change in the 9-bolt IIRC. For the 10-bolt, the 28 spline rear is a bit stronger, but other than that there are no real differences.

Try to find a '89 or newer rear. They have the updated PBR aluminum-caliper brakes which are significantly better than the older iron-caliper brakes.

That 9-bolt on eBay is a good find....3.27 ratio and the updated brakes is a tough combo to come by. Really any ratio other than 2.77 is getting hard to find. Expect $100-$200 to ship it depending on where it is and where it's going. I'd jump on it if you can swing the money and the bid doesn't get too high (paid $425 shipped for my 3.70 rear with the crappy brakes.)

 

What do i need to do to swap over my drum brake rear end to the new disc brake rear end?

 

Bolt it in and hook it up. Then bleed the calipers. That's pretty much it. You can change the brake proportioning valve if you want (I did) but a lot of guys have kept the stock one and reported no problems.

 

I am getting ready to do this to my 89 RS with the Borg Warner 3.27 posi, disc brake unit from an 87 IROC. Anything different with the B-W?? Would it be any better to just change the ring and pinion and add the 3rd member to my existing? Should I just pull the entire rearend from the 87 and put it in my 89??

Thanks

 

The 9-bolt ring-and-pinion won't physically fit in the 10-bolt housing. You'll have to swap the whole rear. It's already set up for disc brakes, and the 9-bolt is stronger than the 10-bolt anyway (assuming your RS has a 10-bolt.) Change the fluid for sure, and make sure you use posi additive.

 

Thanks! You saved me a lot of cussing and aggrivation!!

 

One problem with the brakes is that the Ebrake cables wont work. I don't know which ones do. I bought a pair from the dealer and they were too long, so after a year I still have no ebrakes.