I was searching through my RPO codes and found that my Disc brake rear end has the 3.27 rear end gear. This is in a 1985 T/A, since it has disc brakes does this mean 9 bolt? My old 87's was a 10 bolt and drum so I was just wanting to find out.

 

You don't need a bunch of "codes" for that. Just look up under the car.

 

car is in the shop currently getting my 87 motor and transmission and some other work...

 

Stop by the shop and look.

The "codes" are no guarantee of what's in the car now today 20 years later.