I have located block and/or cylinder head leaks by putting household water pressure into the cooling system with the oil pan removed. It's necessary to bypass the radiator and heater core with some creative plumbing using PVC pipe, then connect a water hose to the block drain port and turn the pressure on. It's also a good idea to have the pushrod cover off to look for leakage there. It beats scrapping what might be an otherwise good block if you can pinpoint and repair the leak.
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!