My 1962 413 (single 4-barrell) is making some good pinging these days. I've checked the timing, which I have set at the 10-degree mark on the balancer (as opposed to the 0-degree mark). Under the distributor cap I have one of those electronic ignition boxes opposed to points. I run the highest-octane gas I can find. Not running any hotter than it usually does. Any ideas how to make the detonating cease? Thanks