Hey guys i have a 05 f250 on 40s and was wondering what would be the best option for gears. I'm moving soon and will be driving on the highway regularly(small town now so rarely sees highway). I really don't have a clue on where to look or what to get. Any tips or info would be awesome. Thanks!

 

With 40's a 4.88 or a 5.XX gear is best!! Brings you near a 3.73 ratio

 

thanks for the fast response and the info! I will look into both of these. Thanks again

 

You want to be in the 1800-2000 rpm range on the highway, so depending on what speeds you run, here is what I would go with:

65 mph - 4.88s
70 mph - 4.56s
75 mph - 4.30s

I have 4.30s with 35" tires and run 65mph (speed limit in Oregon) and I'm cruising right at 2k rpm. Before you spend money on a gear swap, make sure you know what is already in there and that you will be staying with the current tire size.