usually it's right on the oil cap... lol. it's 5w-30 though, same with anything gm makes now and going back a ways. i believe the only thing they made that didn't was the 3800, but it doesn't have any of the fancy cam phasing or special lifters or anything like that, so we put 5w-30 in it at the shop instead of the 10w-30 it calls for. and i stand corrected about the recall, it's not in the oil pan, it's in the oil control manifold that sits in the lifter valley. a lot easier to get to, especially because nothing flows through the upper intake