Limited Slip Additive or Not for 2004 2WD Yukon XL

[jason78]

I have an 04 Yukon XL 2WD I want to change the rear diff fluid on. RPO GT4. I am finding all kinds of conflicting information on forums about whether to add limited slip additive or not. The only thing I have seen for certain is that you don't need the additive is you have a G80 RPO code Rear End (which I do not have) SO, the question remains, do I have a limited slip rear end or not, and do I need the limited slip additive? I'm using the AC Delco 75W-90 Synthetic Dear Lube. Since I don't have G80, is there another RPO code I need to look for to determine if limited slip or not? Thanks!

 

[ccapehartusarmyINF.(ret)]

you have a limited slip diff
limited slip diffs are pretty much standerd even on 2wd
and i have never heard of using limited slip additive