I have seen stock distributors have the big spring let the advance work up to over 5000 RPM shock scope
If the advance is all in by 3000 RPM make sure you rev the motor high enough to not have any more advance after that twocents scope wrench
To much advance can and will kill parts down


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)