I don't know how to tailor the vacuum advance to my engine at cruise speed. Can anyone please describe the theory on that?. I have always read it wants more that the 35* while cruising on the highway. I speculate probably 12* to 18* more, but how does one know what is optimal at steady state cruise and how does one test for that???.
add vac adv amt till you are just under the pinging point in everyday driveing under varying load/RPM conditions on your hottest/driest (most likely to ping) day & the same on a steady interstate cruise (also on your hottest/driest day) & peoples' hearing varies & there is silent ping so give it a cushion. You want to be close to that line but never over it.
