One approach might be to run the engine up to normal operating temp and then advance the timing till it "grunts" back at the starter when starting. Retard till this just quits. Drive and accelerate hard in high gear. If pinging happens retard a fraction more. Check with timing light to see where mark is at as the timing will now be very close to where it should be. You may have a Fluid Dampener or other after market unit but if a factory type this will show if the outer ring has moved on the rubber and thrown off the timing mark.

Evan