I need to find out what gears are in my stock rear. How can I tell which ones I have? I thought i saw a place where you put in your VIN and it tells you everything your car had from the factory. Thanks,
Jason

 

Here are 3 ways:
1- If it starts with 2 on the gear shifter then its a 2.73, if it starts with 1 then 3.23
2- Also the PRO codes sticker (in the glove box), GU2 = 2.73, GU5 = 3.23.
3- If you're driving around 62 mph, your rpm reads 1750 = 2.73, your rpm reads 1950 = 3.23.