Sorry to ask, I searched and could not find anything conclusive. There was reference made to the fact that the early 07's with the 5.9 may have the newer
g56 found with the 6.7's with the taller gears. Is this true? I do about 2000 rpm at 67 or so, at 85mph I am in the 2500 range does this sound like the gearing in the 06's or the 08's?
My build date was 11/06 by the way.

 

never mind searched a little harder and I have the AD not cool updated tranny but now I feel better about the 22.5"s.

 

Yes, my 07 5.9 has the new gearing AE on the trans.. Much better !