I may have been misreading your previous post, it seemed to be of a mischievous nature. If I misunderstood, then my sincere apologies.
Bolt head, a conforming engine is one that has correctly gapped plugs, resistance below 5Kohms, magneto's in a good state of function and timed accurately to the correct numbers, plus fuel/air ratio's that are near to equal on all cylinders. As the design engineers would want them to be.
