I have a 89 RS had been sitting since 01 was last time it was inspected. Pull the 305 and put in a 350 w/Comp 260H cam and shorty headers no cat. Got seats from wrecked 2001 Camaro. Only thing I need to finish is the T/Top headliner and paint. I painted for about 30 years before getting a Manufacturing Production Supervisor position. So I still have everything to take care of the paint. Car is black now going black from mirrors down with 1/4" silver painted stripe and upper med. grey metallic. It currently has a single track 2:73 rearend w/drum brakes. I found on Craigslist rearend from supposedly a 88 T/A man showed me the code on rear end said 3:73 posi track with disc brakes. I bought for 150 brought it home and pulled rear cover, it was a 3:23 rear with posi. I kept it because everything seemed to be fine. I have read all the stickys and want to know what all I will need to swap this rearend to my 89 with 700R. Thanks for any and all answers. Oh yes it is a TBI with 350 injectors knock sensor etc.

 

Check the following sticky for info on combination valves, parking brake cables, and speedo gears:

https://www.thirdgen.org/forums/tran...-10-bolts.html

JamesC

 

Here..lemme actually tell you and make your life a little simpler.

If the rearend you got was from a 3rd gen firebird, it should bolt DIRECTLY up to your 3rd gen camaro. But since your 89 RS originally came with drum brakes, you'll have to mess around with the disc brakes to have it work right. e.g. the parking brake cable to hook up n stuff.

If you're completely sold on getting 3.73s, your carrier (differential) in the 88 T/A rearend should accept a ring gear since they would both be III series. Everything else would line up perfectly (granted it's in good used condition). e.g. spring coils, sway bar, lower control arms, torque arm...etc.

Personally, I would suggest sticking with the 3.23s so that your car would be more streetable than with 3.73s.

 

Thanks for the reply, the rearend came with the coil springs control arms even a aluminum driveshaft maybe the driveshaft will tell more about what year it is. Yes I plan to run the 3:23's should make some different over the 2:73's. Most people can not get the rear setup so it is as quite as factory.

 

Wow...even aluminum driveshaft? Well all of that for $150 seems like a pretty good deal. Maybe just freshen up the posi and you're good to go! Hopefully the bearing are good too.

 

Since your car is an 89, you may experience issues with the disc/disc combination valve that should accompany a rear end with 10.5" rotors and iron Delco-Moraine calipers. An early 89 car will have the correct tube nut fittings (first design, M1.0), while the late 89+ car won't (second design, M1.5).

JamesC

 

What would a '92 Car have?

 

Will post up some pics to see if this is the rear your are talking about. Thanks for answers all help needed.

 

The JG1 shaft will have a part number on the tail, 10085375, but aside from that info and the fact that alum shafts appeared on various thirdgen cars in the late 80's (89+ for practical purposes), it won't tell you much. For example, I swapped one into my 85. If you have a fourthgen alum shaft, the swap, of course, would be obvious.

JamesC

 

Anyone done a swap from 2:73 to 3:23. Was there a noticeable difference especially in acceleration from dead stop?

 

Yes.

JamesC

 

How are the fittings handled if the car is the early M1.0 design & the rear axle is the later M1.5 design?

 

The different tube nut sizes are only an issue at the combination valve.

JamesC