or do I need to get a posi so I'm not just spinning one tire. I can't really spin my tires with my rims how my truck is, so help me out here.

 

Look for "G80" in the list of RPO codes in the glovebox.

 

Is the G80 the locking diff or the limited slip, or are they the same thing?

 

G80 Locking diff
G86 Limited slip

 

I had the locking dif in my truck (also a 4.8). I blew it up in the 1st yr of owning it. Then I bought a procharger kit so I put in a "pro" series auburn. That blew up faster than the stock one did. I now have an eaton and 4.10's and do date haven't had any problems. During race season, I launch at 3500 rpm's on slicks and the eaton has held strong.

 

This doesn't make sense to me cause my window sticker said I had a limited slip, but my glove box has the G80 RPO.

 

working at a chevy dealer in service for 4 years

trust me G80 is a locker

i'm not sure why they write limited slip on the maroney but it is a locker

 

I order these trucks. I work for a chevy dealer.

 

Well, that's good news for me

 

I've always understood that any non-locked rear end is a limited slip (posi). Meaning it will slip some but it is not completely locked, which would be unpractical for daily driving. The standard rear end should be referred to as an open differential. Most dealers around here don't order the posi for most of the trucks on the lot. Don't worry though you'll want to get an Eaton anyway because the GM posi is a POS.