x2 on the de-ionized
de electrolized
reverse osmosis water..
or in a pinch distilled water.
w/ Water wetter.
much lest issue with rust and the galvanic/electrolosis
corrosion of steel block, copper head gasket and aluminum head...
fwiw
cheapst

ps you guys with "well" wter like my buddy in Ohio..keep that out of your block..that stuff is
rust maker on steroids...