EDIT: revised version with more info
First read the tech article on this site
http://www.thirdgen.org/newdesign/tech/4thgenrear.shtml
I wrote another similar thread before (now edited to this) and decided that since i just did the swap, i would clean that post up and add more info and pics. This is what i know about the rears and swap from lots of time searching and my recent experience.
The 4th gen rears retain all of the third gen stuff, all shocks/springs, panhard bar, lower control arms and such.
If you lower the car, get an adjustable panhard bar to recenter the rear… if not it will kick out on the driver’s side. Mine did that with an eibach pro-kit.
LT1 and LS1 A4 cars had either 2.73 or 3.23 rear (gotta check that out) and T56 cars had a 3.42. The LS1 rear is preferred in a lot of cases because of the brakes that usually come with it. They are pretty big at 12inch and big single piston calipers and work good. Up until '99, the 10 bolts had Auburn posi units..(from the best of my knowledge) which is a clutch type posi that needs limited slip additive. 99+ Ls1 cars had Zexel Torsen differentials which are great for strip performance. Although some SS model cars from 99+ did have options for the Auburn unit. Zexen diffs dont have clutches which can wear out in a short amount of time. Just another advantage of the zexel differential.
The 93-97 4th gen rears are 3.8" wider from hub to hub so the stock thirdgen wheels will stick out some. A lot say that its even with the fender lip so its not all that bad. Some stick out abit past. the 98+ rears are abit shorter, at about 3.5 inches wide they say, but my measurements are showing more like a 3.125 inch difference. LS1 rear is about 64 3/4inch long and 9 bolt was 61 5/8. Below you can see my pics, its even with the fender lip.
Also, the rears are available with traction control or without out it. These are called 4 channel rear ends for traction control, and 3 channel rearends without traction control. Since thirdgens don’t have ABS or traction control it really doesn’t matter which type rear you get performance wise. However the brake lines on the rear will be different. The rears with traction control and abs have split separate lines and don’t connect to a T block like the 3 channel and factory thirdgen disk brake rears...so if you get a 4 channel, you’ll want to run new hardlines from the calipers to a T block on the rear end, just like factory thirdgen disk brake cars have. You should be able to reuse your factory disk brake cars rubber line and Tblock and just screw in the new hardlines to the 4thgen calipers. Several members have done this. (82-83 cars might have different fittings for the hardline on the car from what I read, so you might wanna check that) Just measure the new hardline lengths, which should be about 18-20inch on the drivers side and 26-30 inch for the passenger side. Check which type fitting ends they have. i'm not sure on this one. Also check to see if your factory lines will work…I have heard it works as well.
3 channel rearends have brake line setups like our thirdgen cars. The lines run from calipers and meet at a T block on the rear and the rubber line from the T block just screws into the factory thirdgens hardline fitting. My rear was a 4 channel but I had 3 channel lines put on. My car is a 89 with 9 bolt rear end with factory PBR calipers/11.65 inch rotors . LS1 rear was direct bolt on from suspension stuff to the brake lines. i reused my stock proportioning valve and the car seems to stop great! just like before if not better now!
For the drum rear to 4th gen conversion, you can use the stock 3rd gen master cylinder...some have even used the stock-proportioning valve with out problems. However it wouldn’t hurt to put in a disk rear proportioning valve or an adjustable one from summit racing or wildwood. I’d recommend it. You will need the proper brake lines from the calipers to the T-fitting at the rear. You should be able to keep everything factory from that fitting forward just like the disk brake cars above. This comes from the research on this site I have done, so the hardline fittings on the drum car must be the same as the disk cars. The rear brake lines and the parking brake are the only things you'll need to modify when swapping to a 4th gen rear
Now for the stuff that don’t work….like I just mentioned, the only thing that isnt a bolt in deal is the ebrake cables. For that to work, you need to make a bracket to hold the 4thgen cables to the top of the trans tunnel.. or get different cables and mod them to work
LS1 98+ rears go here for Ebrake cable info. It covers part numbers, custom brackets and such. Basically, The Bendex P/N# C1621 are the ones to get, but I guess they are discontinued? So use Tru-Torque# C94597 which are 1460mm long. Page 2 of the bottom link goes into good detail on these cables and mods. Also you can use the stock LS1 cables if you mod them as mentioned in the link. I am not running cables yet, and probly will be buying the ones mentioned.
http://www.thirdgen.org/techbb2/show...=&pagenumber=1 (Need Part number for Ebrake cable for LS1 rear brakes.)
another members ebrake mods and info
http://www.thirdgen.org/techboard/br...ml#post3114935 (LS1 Rear E-Brake Cables)
If you have a 93-97 rear, go to a parts store like advance auto, or pep boys or whatever, and ask for e-brake cables for a 90-92 camaro with rear discs. this will give you the right cables. you'll need two. The 90-92 F-bodies used identical rear disc brakes as the 93 to 97 4th gens. A lot of ppl use the 91 or 92. Get the first design, as there are two I believe.
Few pics at the bottom of this thread… describing stock wheels sticking out
http://thirdgen.org/techbb2/showthre...h+gen+rear+end
Some info on beefing up 10 bolt rears
http://thirdgen.org/techbb2/showthre...h+gen+rear+end http://www.thirdgen.org/techboard/tr...you-build.html (How would YOU build a 10 Bolt?)
10 bolt strength..what power some members are running thru the 10bolts
http://www.thirdgen.org/techboard/tr...-300-rwhp.html (Anyone with around 300 rwhp still on stock 10 bolt??)
Quick run down of the install courtesy of Zepher
Jack up the rear of the car and support the body with 2 jackstands.
Place 2 jackstands under each of the axle tubes.
Remove the wheels
Remove the 2 long bolts the hold the torque arm to the pumpkin on the rear end
Move torque arm to the side or pull it off
Unbolt the driveshaft from the rear end, leave it in the tranny and lay the end on the ground being careful not to damage it or knock the end caps off
unbolt the sway bar from the rear
you can leave the sway bar attached to the endlinks but it will make it harder to move the rear end out from under the car
remove the brake lines from the drums
unbolt the lower control arms from the rear end
unbolt the brake line "T" from the rear end, if you are changing the brake lines, remove the lines from the "T" before unbolting it
unbolt the shocks from the rear
using the jack under the rear end, carefully balance it and jack it up a bit and pull the shocks out of the rear end, shocks will just hang there.
move the 2 jackstands that were under the rear end.
As you carefully lower the rear end, grab the coil springs as they will start to fall out.
roll the jack with the rear end out from under the car and place it somewhere.
Put the 4th gen rear on the jack and roll it under the car.
jack it up about level with the shocks and place the jackstands under the rear.
Position the springs back on the perches and carefully jack the rear up
Bolt up the shocks
Bolt up the Lower control arms.
And just start bolting everything else back up.
And now my LS1 4th gen rear installation pics
LS1 rear end installation pictures from cars photos on webshots
. oh the rear didnt lockup so far. on the stock valve.
