Have you tried colder plugs? I had pinging pretty bad and went 2 steps colder, cut it in half. My engine is 10.2 with iron heads and I can drive it now because of the plugs.
Edelbrock calls for Champion RC12YC plugs. Those made the engine run on and on... even after shutdown. I wanted to try RC10s, but I had trouble getting them. I've ran RC9YCs and they stopped the dieseling completely.
I didn't notice a difference in engine performance or spark knock.
