340 has no balls

So you found you have about 20° initial advance... there's your ping. It sounds like you just need a good tuner to help. Also, have a friend jump in with the engine off and floor the gas pedal. Check to see if the throttle cable actually pulls the carb totally open. Judging at the quality of the work (meaning the way too much advance) I would question the basics now. Also fix that kickdown linkage!!