Audible detonation is NEVER a good thing and its rare to experience it with a no-load test.
In all my years of tuning and doing this for a living I've only ran into a couple of engines that pinged at no load without very much timing in them.
One was a 1974 Super Duty 455 with dome pistons and XR-276HR cam it. The ONLY time it didn't ping was at idle speed.
Had a 460 Ford that I helped the owner rebuild. His original heads were cracked so he was given a set of early 1970's heads. They had "open" combustion chambers in them that I guess are horrible and known for detonation issues. At 9 to 1 compression that engine pinged EVERYWHERE unless you were at idle speed. In order to get it to stop pinging we had to pull a LOT of timing out of it and run only 6 degrees from the VA unit. It was more of a "crutch" than a fix, but one of the many valuable lessons I learned early in my learning curve with these things........
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If you can read this, thank a teacher. If you can read this in English, thank a Veteran!
https://cliffshighperformance.com/
73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile),
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