Is opening the petcock behind the distributor and draining coolant there enough to be safe ? or is there another place to drain engine?

charliej13,

If you are draining the complete system then use the drain under the radiator on the right side. If only the draining the block then yes the drain right rear of the block will do - you will also drain the radiator down halfway down as the coolant levels out. Just a heads up that this drain is usually clog with rust particles from the block. It will still make quite a mess as you turn the valve the stream of coolant will go every which way and trying to catch the coolant in a pan or bucket is somewhat futile with everything in the way.

Andy