How do you determine the gearing of the rear end? I read the sticky about the 4.1 v 3.9 thing and definitely want the 3.9 for better highway mpg, but the guys at the auction just give me blank stares when I ask.
If so the axle label will long since have succumbed to the elements.
Only ways are VIN enquiry with a dealer or actually mark the prop and a tyre and carefully observe relative rotations. Just less than a ratio of four to one and you're in business!