Originally Posted by truckernix
I don't know if I would subject an old rad to 20 psi pressure

That's the reason for getting the radiator and the heater core out of the mix- - - -"Splice the upper and lower hoses together"- - - -That means put the pressure on the engine block and head only, not the radiator and heater core! I've also done that kind of pressure test by plumbing a garden hose to a similarly-isolated block and head, and using city water pressure.
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!
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