Mad Dart
Nothing to see Here!
I had a 360 block cracked through the valley, it was stock & out of a 78 truck...
I think the 600 limit is complete horse sht.
Aside from precise machining & assembly, I believe core shift & tune are the important factors.
JMO
You and I both and by the time this thread is done, there will be a whole new onslaught of believers that this "Myth" is indeed Horse sht.