just a quick question... can you upgrade the stock rear axle from drum brakes to disc?

 

Quick answer is YES! There are a few options. You can purchase the axle from a salvage yard from a same generation Trans Am or there are a few companies that make conversions.

 

You can all pull a rear disc
from a early 80's A- body Caddy, 3rd gen or 4th will bolt up also. Just need to be aware of the back plate thickness, since it controls the play on the axels. Go to Nastyz28.com (all 2nd gen site) and go the suspension topic in the forum section. There is tech information there on the swap.