Is the cylinder head off? If so, it can be magnafluxed or pressure tested for cracks. If not, splice the coolant inlet and outlet hoses together and pressurize the water jacket, then look for leaks. DO NOT pressurize the radiator- - - -that old one will blow out long before there's enough pressure to show up a leaky head or block!
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!