Yes, the valves in that particular cylinder are supposed to be in the head, not the piston.
However, they did not travel from their home due to any issue listed.
A couple more pictures:
Cylinder 6 was the initial failure and as you can see, the block is cracked at the 2 o'clock position in #6 (picture rotated 90 degrees counterclockwise) and cylinder #8 that ate some of the chunks (#6 wasn't selfish and decided to share), cracked the cylinder wall at the 2 o'clock position as well. That whole section of the block was BROKEN all the way to the lifter bores. The tuning that was flashed to the PCM long before I ever saw this thing...well...it was HOT. But that's not why it failed.
The answer will be revealed a bit later but here's another hint: There is a reason the cylinder heads were pictured side by side and keep in mind that this engine was recently remanufactured.