Spark plug issues

[scotty305]

Originally Posted by NoDOHC

...
Anyway, so what I am taking from this is that If I hear something that sounds like metal hitting metal, it is severe detonation and that the pre-ignition is inaudible. That would explain some of the symptoms that I saw on my spark plugs.

Based on Ted's advice, I retarded the WOT timing to 28 BTDC at 3,000 RPM and tapering down to 15 BTDC at 750 RPM and found that the engine felt more responsive. I drove it 800 miles only stopping for gas and the plugs looked as good as new at the end of this.
...
I am thinking that my original theory was incorrect and that the spark plug erosion that I observed during hard driving was due to pre-ignition, not incorrect plug heat range.
...

I'd be very interested to see photos of the eroded spark plugs, if you've still got them.