Anyone have a 6.0L with 4.10 gears? I found a used axle with a locker I am thinking about buying, but it has 4.10 gears. I am not sure I want to take a big hit on mileage from my 3.73's. Just wondering what people are getting for mileage.

Brew

 

8 mpg if lucky also you have to change the frt and rear if 4x4

 

just a 2wd van, so just the rear. From what I have been reading, there isn't that big of a hit, but that is why I am asking.

 

You could compensate by increasing your tire circumference. Go up to a taller tire. Check 1010tire for the handy size calculator they have to see.
You can also google a convertor that tells you your rpm with different ratios....see how much diff it will make at 60 mph.