Ok. Got an answer from guys I know at Nissan Engineering
"As it turns out we are not going to need your friends Titan. There was a design change between 05-06 MY for the axle shaft, side gear, & snap ring specs, and also the pull out force spec. Although we still have some pull out issues now, prior to 06MY we had many more. FQI would still like your friend to fill out this questionnaire after the repair is performed."
So................to answer the question about the two part numbers of the front diff's.
#38500-8S102 = 2004 thru 2006
#38500-8S11B = New designed diff. addressing the issues.
Make sure you are armed when talking to your stealership. Flat out tell them that Nissan engineers redesigned it due to the above issues.
Please note that the titan was orginally engineered in Japan and that the US nissan engineers told the Jap's about the abuse we put on our trucks. Now the US engineers are fixing their f-ups.