Because the KB-107 slugs come in decently high and the usage, as you said, is f a .028 head gasket on a zero deck engine and iron heads @ 72 cc’s, IF you have a 72cc head, is 9.8-1 or better. With a small cam, the cylinder pressure is very high and no amount of quench will solve your pinging problems. You’ll have to dial back the timing in order not to ping even with 93 octane and you’ll end up loosing a lot of power.
File fit the rings without a torque plate on.
What heads?