Whats the best way for me to confirm this? I'm thinking I don't have the Eaton, since everyone is telling me that would see that G80 code if I had one. I would love to be wrong though! :)

Thanks again.

If your dial just has 2HI and Auto, then maybe you don't have the Eaton G80 locker in the rear. Maybe just the optional 2spd transfer case has the G80. Not sure.

Jack up the rear and turn one rear wheel (in PARK) and if the other one turns in the same direction, then it's a locker. If not, then it's and open rear end.

Shark, are you sure about that ?
If you lift both wheels, leave it in park, then...
NEITHER should spin, when in Park,
IF it's a Locker. Isn't that right !

If it's a standard (Spider Gear) Rear End, then...
When in Park, if you spin one wheel, the other
should turn the other direction.
That's the way I do it.

Yeah you're right. Was watching a movie and not thinking. :(

I definitely have 2W, Auto, 4L and 4H.

If I had my thinking cap on, I would have figured this out before I bought the Suburban. But even if its an open rear end, maybe I can still a G80 or similar installed.

I appreciate all of the responses.

Shark,
HA, thank you for that ! You don't realize how infrequent guys my age
have the clarity of mind, where we can make observations like that !
Keep um coming ! :D :D

powernoodle,
YES, you certainly can, BUT...
1) You must have the identical ratio installed, as is in the Front Drive, and...
2) Using your existing Ring/Pinion usually doesn't prove to be a very long lasting fix, and...
3) That would be a job for a Pro. Setting up a third member is tricky at
best. I've tried a few, and it's a waste of my time and money. Better
spent a labor charge, and have it done right.