Andrew k

From what I've heard 3.73 gears and 37" tires will put a six speed at around 1600rpm at 70mph. I do mostly empty highway miles so woudnt the 3.73s actually be better for me than 4.10s? I am not out so much for acceleration but definately don't want to lose speed pulling moutain passes. What do you guys think?

BigBlueDodge

1600 RPM's sound a little low to me. I run BFG 315/70/17 -> 34.4" tires and at 70 I get a hair under 1900 RPM's. I have 3.73 gears as well. With 37" I wouldn't think it would drop 300 RPM for just 2 inch diff. I'm guessing you will be around low 1800's for 37's at 70 MPH. For empty driving on highway, the 3.73 gears and big tires, the 3.73 gears will let your engine run at lower RPM and thus better MPG. Empty, I don't suspect you will lose any speed pulling mountain passes. Put a trailer with any sizable weight, and I'm willing to bet that you you are gonna need to drop a gear on mountain passes. Big tires look fantastic, but without regearing you are loosing torqe.

blown32

I also have 315s and 3.73s. If I had it to do over I would go with the 4.10s

Empty is great, no down shifting and I can pull the passes faster than I can take the corners. But even with 8K enclosed car trailer it could use more gear and I only got 10.2 mpg on my last 250 mile tow at 65-70 mph.