Any scout II axles after '74 will work. They were standard discs in '74. I got a website from JEEPN. It's saved on my favorites at home. I'll repost if you haven't got an answer when I get home. The ratio is usually on a tag on one of the cover bolts I think but isn't too hard to figure out if not.
You will have to be very lucky to find a pair with low gears. The 78 Scout I got my axles from had 3.07. I believe 74-80 are the years you are looking for. A Wagoneer front axle is actually a better swap, you still won't find on with decent gears, but it has better caster. With the Scout axles you will have to cut and turn the Knukles for correct caster.