Tooth counts for AMC 20 and Dana 30 are identical for all ratios except
3.54:

http://www.xtremeterrain.com/p67.htm
http://www.xtremeterrain.com/p56.htm

Also, having two Danas doesn't guarantee identical ratios. My Dana 30 is
41x10 (4.10). My Dana 35 had (4.11). My Dana 44 which would normally
have 45x11 (4.09) has the 41x10 (4.10) TJ Rubicon gears. Granted, these
differences are probably smaller than that between your Dana and Ford,
but you can't say that front and rear Danas will necessarily 'exactly
match'.

Steve
http://xjeep.dyndns.org


L.W.(ßill) Hughes III wrote:
> Our Transfer cases are likely to bind coming out of four wheel
> drive on good traction, because your AMC 20 and My nine inch do not
> exactly match ratios with our front ends. Something Mike doesn't
> experience having both front and rear Danas.
> God Bless America, ßill O|||||||O
> http://www.billhughes.com/
>
> Jeff Strickland wrote:
>
>>But Mike, he was told to go in reverse to allow the mechanism to unlock. I
>>was thinking he has the system like that in the YJ. It turns out he has the
>>system that is like the TJ.
>>
>>This is not entirely true. Well, it is true in theory. That is there is no
>>requirement, but we all know that the YJ's front axle can balk at unlocking
>>when the tcase lever is moved back to 2WD, the work-around for this
>>balkiness is to back up a few yards.