On another web site there was a discussion about the DQ when she "ran through herself" at Rock Island in the fall of 1954. I raised the question "how close does the piston come to the cylinder head when the stroke is at "top dead center?" No one on that site offered an answer so I went to the expert, Chief Kenneth P. Howe, who said the distance is a mere 3/8ths of and inch!
That tells me that when the pitman strap broke it didn't take much of a distortion to drive the piston into the cylinder head.
Just thought you may want to know.....who knows that maybe the final answer on JEOPARDY one of these days and you might win a bunch of money.