My buddy has a 2006 4X2 Ram. He is set on a 6" lift with 35 or 37" tires. He doesnt know what gears he has now but it has 20" rims on it so maybe that will help you guys figure it out. He is thinking of going with 4.10's. From what I have read I think he may need to go 4.56 or even 4.88. What do you guys think? Gas mileage?

 

Nobody reads this section?

 

I would bet he already has 3.92 gears, that is what my brother's Ram came with. I would go with at least 4.56s with a tire that big. My brother now runs 4.56s in his ram with a 29" tall tire.