You can also plumb an air hose to the block drain and use compressed air to blow the crud out of the way. Just be sure to remove the radiator cap to prevent destructive pressure from building up in the cooling system. Once a somewhat clear drain path is established, some aggressive flushing can be done with various chemicals.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!