Help me diagnose why my head gasket blew

I may be an hour late and a dollar short but here is my opinion. PING!!!! You mention it had a ping. Pinging is caused by improper detonation. Either by hot spots, low octane fuel, excessive heat, or too much timing (picture hitting the oxygen lever on your acetylene torch and it will give you a visual). I have found timing to be the culprit in most cases. You may have too much or too soon advance curve in your total timing. Your hot spot was where the gasket failed. Find the cause of the ping and you shouldnt have any more gasket troubles. Dont rule out that the gasket could have caused the hot spot and destroyed itself. Although If your PCM is stock and your engine is not, I'd bet it cannot adjust enough within its original perimeters. You may need a chip at the very least or even an aftermarket PCM. The chambers dont look lean but unless you pulled the heads after a hard run it will only represent the idle mix which is probably way too rich to compensate for the lean driving condition. I'd find a good performance shop in your area to work out your PCM woes or invest in a good programmer and start teaching your ride how to play nice. David