Well, I have a spare Dana 20 on the shelf out in the "shop"/garage. It came from an auto 1979 Scout II....so I'm missing the input section found on the manual versions, but did get the "bull gear" from the end of the transmission. Anyway, I have it as a spare for my 75 CJ-6. Short of taking it apart, is there an easy way to found out the info you seek? I would think the gearing would be the same, but who knows.
1975 CJ-6 1983 CJ-8
1986 CJ-7 Laredo 1986 TJ-7 Trail Jeep
2003 Inca Gold TJ Rubicon