Ya 4.10 is more common. You can have any ratio made up to your liking from my understanding. I almost went with 3.83 gears but the shop I went to showed me the power bands and RPM ratios and the the 4.10 was the ticket. At 85mph I am only at 2500 RPM. In town my mileage statyed about the same and I gained a little on the freeway trips.