there were two maybe three pistons from the factory. Those look like slipper skirted low compression (7.3:1) full dish. There was also a 'D' shaped disk that 8.? compression, and then another that I'm not sure if it was factory, but the dish was half as deep (9.1:1 compression) used for engines running LPG. There is no indication that they are Hypereutectic pistons.
http://en.wikipedia.org/wiki/Hypereutectic_pistonLarry
