Is it 9.25 or 8.25? I think it's the 9.25. I'm interested in putting in 3.92 gears in it because I only have 3.55's and I want to tow. I just need to know what size gears to order. I heard there is a 3.91 gear for Dodge but that doesn't pertain to the Durango does it? Anybody know where to get inexpensive gears? I was thinking Summit. How much do you think a pro install would cost? I'm guessing it would raise my rpms about 400 or so at highway speeds correct?