340 Pinging using 94

This ^^^^^^^^^^^^^^^^^^ right here.

Pinging while coasting is not combustion related. You have mechanical metallic thingys touching each other. I knew a guy once that thought he had "pinging" while decelerating which is IMPOSSIBLE BTW.....Turned out to be the flex fan just nicking the fan shroud.

As mentioned--cranking compression would tell me all I need to know. I hate threads like this that suck me in and leave me hanging. Lol. J.Rob
I agree more load gets you closer to conditions that cause ping. So can leaner fuel mixtures. I have never experienced ping when actually "coasting". If what the op describes as coasting is actually coasting it's not likely what he is hearing is pinging.
I have experienced pinging at light throttle and had it disappear with moderate throttle (increased load). I suspect due to the power valve opening making the air fuel ratio richer. I can't confirm that so it's just a theory. It could be the op's "coasting" is just reducing throttle position and speed just enough to close the power valve while still having enough load to cause ping. Hows that for a conspiracy theory?