How do you know if your truck has the g-80 rear diff vs just one with limeted slip. Mine will spin both tires 80% of the time but if I am already turning right then mash it most of the time just the right tire. Does one of the #'s in the vin tell me this or do I need to pull the cover?

As far as I know it either has a G80 or an open diff. If you really want to know if it has a G80 just look at the sticker on the inside of the glovebox door and you should see G80 listed on there somewhere if it has it.

Ok thanks it must be g80 it locks up to much to be open. I will look in glove box.