Is there Vacuum Advance at idle? And when do I want all advance in? Last, at steady 2500 rpm how much advance do I want - for breaking in the new performer RPM cam?

I have '69 SS 396 - 350 HP - son and I completly restod the car Stock Heads warm cam - headers and 3 inch - ACES member

The vacuum advance can is:

VC680 B1 1969 396 Exc. High Perf. starts at 8-11", 8° @ 16-18"

If you have 36° centrifugal advance and add 16° vacuum advance, you will have about 52° advance under high vacuum conditions.