Rookie here and don't mean to steal your post but how do I tell what gear ratio I have and what axle? I have a 68 2 ton with a 5 speed tranny with th 2 speed rear axle. And side open in high does about 50 and sounds like it's gonna fly apart
There's a couple ways to tell. You can located ID info on the axle and research it and find out - or you can open it up and count gear teeth (divide the number of teeth on the ring gear by the number of teeth on the pinion) Or you can jack it up and turn the axle one revolution and count how many revs the driveshaft makes. This last method can be complicated if you don't have a posi unit in the diff. What I usually do is jack it up and block one wheel - then turn the other wheel TWO revolutions and count how many turns on the driveshaft. The result will be the same because of the gear reduction through the differential. I'd say your truck probably has at least a 6:1 final in high range.
