hey guys
just wondering if anyone can help me out with gearing recommendations for my truck the gears are stock right now.

i have a 06 f 350 with a carli lift and 38 inch tires
head studs, egr delete, idp street tunes and mtw hybrid turbo
i dont tow often but do probably equal city and highway driving.
also im up and down logging roads fairly often.

i would definitely like to see it quicker off the line.
thanks

 

So currently you're running the factory 3:73 (axle code 3L on the door sticker)?

Here's a handy chart with all the Ford axle codes:
Ford F-250/350 Series Gear Ratios

 

4:10-4:11 would allow you to go to 40" if you want probally, better mpg in city. should bring you rpm's up to what you stock rpm's were with stock tires. A true 4x4 shop or speed shop could help you out better.

 

yes im currently running 3:73

 

Use the new gear formula. New tire diameter ÷ old tire diameter x current gear ratio = new ratio.

 

What rpm are you turning at 65mph? I run stock size 235-85-16 (31 inches tall) with factory 4:10 gears, and my truck is a beast off the line. At 65mph its turning 2000rpm on the nose. With you running 38"s I would think you would need to go lower than 4:10... Maybe 4:56 would be closer to what you need.