I have tried the advance to ping method also, as well as vacuum, as well as setting timing where it seems to run best... each method gave a different timing setpoint when checked with a timing light. The motor is a 1962 261. the distributor is in good condition, vacuum/centrifugal advance seems to work properly (as checked on dial back timing light at diff rpms)
overall I have no problems with how the motor runs but it seems like having a target range for setting timing would allow for checks and better repeatability when doing tune ups.. it just doesn't seem like "custom" settings should be required.
I have run the motor from 4BTDC to the 14BTDC noted above ... it runs a little better at the higher advance settings but doesn't seem to idle as smooth at low rpm with the more advanced settings.. again...not a problem just observations
what timing settings work best for you guys?.... whats your timing set at?