Head gasket - where's the leak?

[AZPete]

I had symptoms of a head gasket leak (overflowing expansion tank, erratic temp gauge & white steam from tail pipes) so I flat-bedded home. When I pulled the header I poured out a quart of coolant. I pulled the engine and the left head showed coolant in both cylinders but I couldn't see any obvious break in the metal gasket.





Next, I pulled the right head and found essentially the same - both cylinders had coolant and I couldn't see any obvious gasket break.





I'm puzzled by coolant leaks into all four cylinders. Is there anything that could cause that? Since I was trying to nurse the car home after the first symptoms, maybe it was when the second gasket blew that the steam erupted and the engine quit. I'd appreciate any experienced eyes to tell me where the leaks are, and why both heads leaked. Thanks.