UPDATE - After scraping the carbon off the piston tops and wire brushing them, I didn't find any stampings to indicate over-sized pistons. The number inside the skirt of the broken piston is 1858663, a Chrysler part number. According to my local machine shop, his sources say this is a "high performance" piston, and they want $125 for one. Can anyone verify this? Surely, I should be able to obtain a replacement piston for less than this? All suggestions appreciated, thanks!

Roger