I have a non-posi rear/Drum brakes on my 84 Firebird. A friend has a 1985 T/A with Posi rear/Disk brakes. Is it worth swapping out my 3.43 non-posi/drum setup for his 3.23 posi/disk setup? I do not know how good the 1985 Posi units were, but I have heard stories about the brakes.

Anyone have advice on this?

BTW if it makes any difference it will be going into a 1984 V6 Firebird, T-5 Tranny.

 

As good as any Limited Slip 10-bolt rear of that age, if its working. And the rear disc brakes do suck, but they can be made to work.

 

Yes last time he had the car runing it was working. I had been under the assumption that the mid 80's posi's had a reputation for seizing up quite regularly.

 

The Lmited Slip (aka Posi) does not sieze up but starts to slip. So if you do not abuse it and add the correct fluid, the result should be a longer life for it.