I just thought I would add this for anyone like me that has put bigger tires on their truck and wants there speedometer to read correctly. I was waiting til I tried this before I posted anything and the speedometer in my truck with 36 inch tires on it is now within 1 mile an hour at 80mph according to my GPS unit. The Website that lists all the speedo gears is
http://www.transmissioncenter.net/speedometer_calibration_______va.htm
you have to go a pretty good ways down the page to get to the ford stuff, you can also get most of these gears at your ford dealer. There is also a calculator on that page that will tell you want gear you need depending on your rear axle ratio and tire size.
http://www.transmissioncenter.net/speedometer_calibration_______va.htm
you have to go a pretty good ways down the page to get to the ford stuff, you can also get most of these gears at your ford dealer. There is also a calculator on that page that will tell you want gear you need depending on your rear axle ratio and tire size.
