Radiator replacement - Draining the Coolant?

Look, I know this sounds as basic as it gets, but you would not believe the mis-information floating around out there. The manual (Chiltons) identifies the removal of the draincock on the bottom of the radiator and the lower radiator hose as the only items that need to be loosened/opened/removed in order to completely drain the system. I tried this and only got 2qts from the system. Is there a lower drain screw on the block or a bleed screw I'm missing somewhere in the cooling system. Thanks in advance. Jay