There don't seem to be any drains for the Silverado, but there are on the Lumina. The drains are on the bottom side of the block. The front drain is between the starter and oil filter. The rear drain is on the exact opposite side of the oil pan from the front drain. You might have a helluva time with the rear drain, though. I wound up not bothering with it on my car ('00 Monte Carlo). You should open the air bleed on the thermostat housing when draining.