One other test before you pull the head is possible, if you choose to do so. Get each cylinder near TDC on the compression stroke, set the handbrake and/or chock the wheels with the transmission in high gear, and put air pressure into the cylinder with a quick-connect air fitting brazed into a spark plug shell. Then listen for leakage at the carburetor, tailpipe, and oil filler cap. You can pinpoint intake and exhaust valve leakage, and piston ring leaks by where the escaping air noise is the loudest. Bubbles in the radiator would indicate a cracked head, or a blown head gasket. Air coming from the next spark plug hole in line shows up a head gasket blown between cylinders.
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!