I recently purchased a 2001 silverado 1500, shortie, stepside, with a 5.3L. I was hoping the truck had a limited slip differential in it, but when I had it on the hoist, turning one wheel caused the other to turn in the opposite direction (I believe they turn in the same direction with LS??) Anywho, I was at the dealer, and he told me to look in the glovebox, and if I see G80 anywhere there, that it had a limited slip differential. G80 is one of the codes on the sticker in the glovebox. How can I test to be sure that it does have limited slip, and more importantly, it is working correctly?