Im sure there are more of them broken as Hank is suggesting. Also by design, those pistons are never going to be up to the task of living in a blown app because the top ring is too exposed to the boost pressures and heat because of the huge chamfer on top. The custom forged pistons made for this type of application place the top ring well out of harm's way much further down the piston and protected by the full thickness of the ring land. Again, making it much more tolerant to the heat and abuse seen in force induction apps.
