I've outlined the procedure several times, but here goes again- - - -

Get each cylinder at, or slightly past top dead center on the compression stroke- - - -
Set the parking brake or chock the wheels with the transmission in high gear. On an automatic transmission vehicle, use vise grips on the flywheel to keep the engine from turning.

"Easy button method"- - - -line up the distributor rotor with the cylinder you're testing.

Make a pressure adapter by threading a spark plug shell with the porcelain insulator removed with a 1/4" NPT tap and screw an air line quick connector into it. Use thread sealing tape or pipe dope on the quick connect to make sure there's no leakage at the thread. Screw the adapter into the spark plug hole.

Set the pressure regulator to 100 PSI with the air line disconnected and no airflow. Connect to the cylinder and record the pressure- - - -90 PSI would be a 10% leakdown rate. Listen at the carburetor, tailpipe, and oil filler to find out where the leak is happening. Intake valve, exhaust valve, or piston rings. Bubbles in the radiator indicate a leaky head gasket or a cracked head.

Works every time and it's MUCH more accurate than a compression test.
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!