The valve head didn't make it all the way to Mr. oil pan like the piston.
Those chunks? They did come through the crack. Before the head was pulled you could see the cam and lifters through the exhaust port.
This is sorta what happens if you put big valves in a 915 head, put them on a 361 block, and don't check carefully enough to see if the valves are going to hit the cylinder walls. There were divots at the tops of the deck of every bore where the valves were hitting.
I'm trying to remember correctly but it seems like it was still making well over 500 HP when it let go.
