What gears with OD A-833?

The tire diameter makes a big difference too. The numbers i quoted were using a 27" tall tire. 275 60 R 15.

If you do the same calculation using a 225 60 R 15 , a 25" tall tire the numbers are off by as much as 1000 rpm for the approx same mph.

Once your sure of the diameter of the tire your going to run, or have to use diameter wise then figure your rear gear.