I have wiped out a 428 due to inaudible detonation. Never heard a thing. Perfect hearing.
5 broken pistons and pounded out bearings.
I ran Edelbrock water injection on my '67 GTO in the late 1980's with the stock 670 heads and 92 octane gas. Didn't help. Had to retard the hell out of the timing. Changed the heads later on to 87cc iron heads.
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Jeff 
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