Mine is has the z-71 package, 3.73 gears and oil cooler, pretty sure it has a trans cooler and i have the tow package (class V), have the same springs as a 3/4 ton and 14 bolt 9.5" rear with the G80 LIMITED SLIP, not a locker, to my knowledge their is no actual "locker" made by GM and it certainly would never be standard. But seriously guys, talkin about how its not worth the cost for the factory z-71 and tow package and all...who in the hell in thier right mind would run around tryin find all this stuff from retailers or junk yards just tryin to save what? maybe a hundred or two or three? so what you have effectively cut cost and wasted time where as it is much easy just to buy the factory installed package especially when some of the things are available only thru GM. To me when you can be able to buy something all at once and know that it was specifically designed for that vehicle but you in turn try to save a few bucks by doin on ur own is just foolish and pointless.
Just my
