I'm a little sketchy on the factory ratios. I didn't know the 2.73 and 3.73 were available that early, and I thought they had stopped using the 4.09 ratio in CJs by then. Weren't there a couple of others too at one point? Like a 3.23:1?
Thinking about it now, I can't remember ever owning a CJ that came with anything other than 3.54:1 from the factory :? That has got to be the most common ratio.
*3.07:1 and 3.54:1 were the only available ratios in 1979 according to the factory service manual, so 3.07s were available in other years than 80-82. That's the newest CJ FSM I have.