the engine diagnosis game!

Crankcase pressure goes thru the roof so oil will get pushed out.

On the gasket.. the only reason it would pop there is either it pinged/detonated when you got on it, or the head or block isnt flat enough, or it wasnt torqed properly. If you look, number 7 also looks close to breaking and was pushing gasses into the crankcase too. Looking at it, I'd say it's not flat. I would use a machinist's straight edge to carefully inspect them both before you reassemble it. So did it ever ping? Carefully clean the carbon off the pistons... are there any tiny pits visible in the surface? Use a strong light and magnifying glass... look a tthe ceramic on the spark plugs.. any flecks of metal or tiny blueish/black spheres stuck to it? Most blown head gaskets are symptoms... not causes.