Someone mentioned 0.63 OD ratio as a good idea.
I don't think it is a good idea for a truck with limited HP.
A common OD ratio is 0.73 or 0.75ish which can feel like quite a gap in the gears from direct to OD. A faster OD yet will be even worse getting into it.
A fast OD might be nice on paper but consider how it fits into actual driving.
I have had a few trucks with 0.80 OD and that is a nice ratio for driving because of the closeness with direct drive, you can usually run the same MPH in either gear as the road conditions dictate.
0.80 is not for making good road speed out of poor axle gearing, but with the right axle gears makes for a nice OD for driving.
Grigg
