Well when I was doing my engine swap when I went to disconnect my driveline I discovered that my car has positrac. I assumed it was aftermarket. Then, when I was going through my RPO codes the other day I found this: AO1- limited slip rear end. So, aparently the posi is stock. Anyone else have this? How common/uncommon is it because my other 84 (non SS) did not have it. Was it standard for all SS?