Use a delay flash timing ight and plot an advance curve by checking the centrifugal advance every 200-300 RPM from idle until you get to maximum advance. In general, most engines perform best with 34-36 crankshaft degrees of centrifugal advance that comes in as linear as possible from just off idle and maxes out around 2800-3000 RPM. Add another 8-10 degrees of vacuum advance for cruise fuel economy. That will disappear as soon as some load goes on the engine and you'll be running centrifugal advance only during acceleration and anytime the manifold vacuum drops a noticeable amount. I've spent 40-something years tinkering with spark advance, either on a Sun distributor tester, a dyno, and/or a delay flash timing light.
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!