Plug readers: What would you do??

Well, that settles that. Now to determine the cause. I think it's because of the backfiring I've been experiencing when decelerating from 6500 rpm at zero throttle it's been popping 2 or 3 times around 3500 rpm as it comes down. I thought it was just in the exhaust, but the carbon in the intake sections of the head indicate it has been backfiring. It's been doing that for 3 races now, never did it before. I don't know if the blown head gasket cause the backfiring or if the backfiring caused the blown head gasket. Parts on order...

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