I just taped a piece of string to my drive shaft, marked a tire and pushed the truck one tire revolution, then counted the turns of string around the drive shaft. Typical low tech approach! Here's one that Chris gave me a long while back. http://www.4lo.com/calc/gearratio.htm
Well yea but I posted to to help those who are out hunting for gears or a axle laying in junk heap some place, you know just thought it might help some body