Where is the coolant drain plug on a 4.8L Chevy?

The coolant drain plug on a 4.8L Chevy is located on the bottom of the radiator, near the driver's side. It is a plastic petcock with a small square head. To drain the coolant, place a drain pan under the petcock and turn the petcock counterclockwise until it is fully open. When the coolant has stopped draining, turn the petcock clockwise until it is fully closed.