Pinging

I'd betcha the vacuum advance at part throttle is causing your problem.
Part throttle throws a lot of advance in. (like cuising around the block.)
Try what the others suggested and disconnect your vacuum advance first thing to stop the pinging.
Then deal with the details as the guys described.

FYI, vacuum advance adjusting doesn't change how much advance comes in, but only when it comes in in relation to the throttle openings.