Have run engine with or without vacum hooked up.

Distributor advance is 20 degrees.checked.

Repro mufflers and resonators. 2,5" front pipes and rest 2 1/4".

Last summer drove the car with around 9:0 comp ratio, with a comp 268xe.
No problem with detonation or pinging, same distributor 18 intial 38 total.
stock metering plates front and back.same exhaust.
5600RPM.

I still think the plugs should have more color on them.

Peter