Thank you Big Truck Driver, R Pope, Rspears, Kitz & DA 34 Guy... Gee I have no idea what the static compression ratio is. I will call & ask Big Al, buy my guess is that he doesn't know either. I didn't hear a ping, I just figured that's what it was cuz it was running bad. I have a retart switch {msd} to retard timing up to 3 degree's per pound of boost & even at 3 degree setting it still runs bad. Also it back fires at high RPM. The local airport just had the 100 octane, nothing higher. thanks again, Bill