[Gholan]

these are the specs as listed by hummer for H3T

3.7L Manual: 45.1:1 with Opt. off-road suspen. package 68.1:1
3.7L Automatic: 36.8 with Opt. off-road suspen. package 56.2:1
5.3L Automatic: 33.1:1 with Opt. off-road suspen. package 50.6:1

I can't remember for sure but, I believe since the off-road suspen. package comes with front locker the cast iron dif is a part of it.

I hope that helps