I believe track pack axels are painted .I remember Reading about the finned rear cover means track pack which comes with 3:73 and Torsen differential but I see a lot of BMR upgrades so this could be a cover change only.
There are several ways of confirming what gears you have.
HOW TO: Determine the Rear Axle Ratio you have - Modern Driveline
Knowing your rear end’s gear ratio is crucial when you are considering a transmission upgradewww.moderndriveline.com
Did you figure out what you have for a rear axle ratio?Thanks guys! I appreciate the help. I’m just gonna have to get the car on stands and spin the tires. And count how many times the driveshaft spins, before the wheel gets back to its mark. I believe thats the only real way of knowing. I Just thought it was odd that the sticker on the axle said that BB and the one inside the door GG. I was already thinking of swapping them out for some 3:73s. And hopefully I won’t have to.