Unfortunatly I don't think anyone makes a 2 series carrier any more. Which means you would have to change gears also, I think 3.08 is the highest available for the 12 bolt. Consensus seems to be that the 3.31's are the best all around choice for a driver. I believe you can go as low as a 3.90, but that is pretty much short trips or track only, you'll be turning a lot of rpm's. Lube capacity is just over 2 quarts but that includes what is in the axle tubes which never drains. When changing it you'll put in just under 2 quarts. Drive it around with a few left and right turns then recheck it.