Good Initial Timing and Too much Total Timing Problem. Seeking guidance to minimize total timing. 1969 Swinger 340 4 Gear

Initial Advance - engine at idle and vacuum advance plugged

"all-in" - vacuum advance still plugged, increase engine RPM until timing stops increasing. This is where you want 32-36ish. I'll add, this is the combination of initial plus mechanical advance from the weights in the distributor.

Then when you add vacuum advance it can shoot up into the 50's.