Mild 318 pinging

You have good idle vacuum, so less vac adv at IDLE is needed [ MVA ],
but some is still desirable. Once you are cruising, the engine sees no difference between PVA & MVA.
So I would use about 10* init & add about 18* [ not critical ] of MVA so that the engine idles with ~28*. You achieve this my making a stop for the VA unit to limit plunger travel to provide the 18*. Adjust the Allen Key fully CW. Check with a timing light & make sure you have 28* at idle with VA connected. Do this, idling, in gear if auto. Turn AK 2 turns CCW & recheck timing; do this procedure until timing falters or drops. Go back 3 turns CW. Job done. If you get pinging, it is better to limit the centri curve with a lighter weight &/or heavier spring, than touch the VA.