Coolant Drainage (Dave Kase)

If engine is warm (just shut down):
Unhook the lower main radiator hose while the engine is still fully warm. At this point the thermostat is open and the block water will drain through the main rad. The thermostat is open if all the radiator hoses are warm (remove cover in front of main rad to get to hoses). This should be done as soon as possible after the engien is shut down. If only 3-4 quarts of coolant come out, the thermostat is closed and the block will still have coolant in it.
If engine is cooled down:
The Bentley says to drain the engine by disconnecting the lower main radiator hose and the heater hose from the engine. The heater hose connection is buried so disconnect the left hose from the firewall heater connection. Then lower the hose below the block connection to drain the block. This method is a bit messy as the coolant drains through some components under the hood.