Canted valve is correct, there is a plug (square) on the driver's side of the block...in the back under the exhaust... you can take this out or you can just remove the radiator hose...your choice. Thanks for the corrrect info CV...and sorry for my incorrect information...you learn something everyday in this place. Todd P.
There is a plug on both sides of the block on all three of my Clevelands. Pulling the lower hose will not get out all the coolant, but will remove most. If you pull the lower hose and the block plugs there will be little to no coolant left in the engine / block.