The Stovebolt Site Forums The Shop Area General Truck Talk how to tell what gear ratio?

Jack the rear of the truck up. Put it in neutral. Mark the driveshaft and mark a tire with chalk. Rotate the tire 20 times. Count how many times the driveshaft turns. If the driveshaft turns 41 times you've got 4.11's. (whatever the result is of rotations of the driveshaft, divide by 10).

Edit. If you've got a Positraction, simply rotate 10 times instead of 20 and divide by 10.