Oh wow so that is a crack. Do you think nitrous played a big part in that? Were you running stock pistons and rings when that happened? The stock setup has very tight clearances. I wonder if that caused the piston to exert more force on the cylinder wall than it should have? Also 600 passes is nothing to sneeze at, specially judging by the pic in your sig I'd say those were not easy passes.
I definitely agree that how you drive it has a lot to do with it. You could make ~5 pulls to get the tune set and then drive it back and forth to work at 55mph and theoretically it'd last forever. It's been a lot of fun seeing what we all thought to be the "limit" from when i first joined the site in '03 until now.