You can either look on your window sticker or you can crawl under the truck. There should be a sticker on the rear axle saying the gear ratio...3.21, 3.55, or 3.92.
Also, you could tell us your tire size and RPM's at 70 MPH. We could calculate which ratio you have that way.
Also, you could tell us your tire size and RPM's at 70 MPH. We could calculate which ratio you have that way.