No, the ONLY way they drove the iron headed test into detonation and run on was to load it down to death and force it to do that.
That would be the same as pulling a 6% grade that’s 4 miles long and you never down shift while pulling a trailer.
That’s exactly what they did. Until that point, the iron headed engine was no more detonation prone than aluminum heads.
Go watch it again.
If guys had EGT’s and they watched them while loading the engine like that they wouldn’t do it. You can drop the temperature just by downshifting to pull the load.
Aluminum is not any more detonation resistant than iron.
I’ve been proving that for 35 plus years.