Engine requires 20 degrees of initial to idle well...

72bluNblu said
if you just look down the #1 spark plug hole with a flashlight while a buddy turns the engine by hand you can get fairly close,.

You and I were doin' OK 'till you posted this. Not accurate. Not even. Piston stop is the "only" practical way. There are others, using fluids and manometers, balloons, and hell, I don't know, a seance, maybe