im sure theyre the standard 8.5" 10 bolt
the front diff is more than likely 8.2/8.25" 10 bolt.

Had to look this up for my 98 Yukon 4x4

 

I called the dealer and found out what I needed. I have a 10-bolt 8.50 / 8.625; rear end, they could not pull up the front. I am guess what I found before is correct 8.25", I ask Ron after sending the info for the rear if they knew. I am waiting a response.

 

2010 would be 8.6 which is the 8.5/8.6 gear set. but front I think is 8.25.

 

i just finished putting my rear togethe.pulled it apart and put the cover right back on. needed a differential.boutght a truetrac and a master install kit from ron. every single thing you need will come in that kit,even with extras minus the oil to re fill the rear. by far the best price rons machine service

 

Thanks everyone, I am going with Ron's Machining Service once I do buy. I bought my truck with the optional Eaton Locking Diff. Would there any benefit at all to purchase a different one? The options for upgrade are either Yukon Duragrip or Detriot Truetrac anyone have opinions on these locking diff's?