Can some of you with the 6.7's and auto trans tell what RPM's you are turning @ 70mph. I'm looking to see if it's worth doing a gear swap from 3.73 to 4.10 when I put my 35's on next week. I need to know what size tire you are running and what gearing you have. Like right now with my 33's at 70mph I'm turning 1700rpm with 3.73 gears. I'm look to see the range from stock tire's to 35's and see how many rpm's I'm going to loose because it seems if you lung the 6.7's the fuel mileage gets worse.