Here is the dirt on the piston & heads. First photo is my piston, which I have found out is in fact the original Mahle piston. This will fit all 11-14 cylinder heads and is the correct piston for all of these combos. So thankfully I don't have to buy new ones.
2nd photo is a piston with magically the same number on it, but quite a difference! It won't fit into the chamber of the BR3E heads used on the 2012 302/325, the 2014 302/350, or the 2011-2014 302/380. However it does fit into the chamber of the Boss 302 head used on the 2013 302/350 and also the 2015-up Gen 2 Coyote heads, as well as the GT350 Voodoo head.
So how was this piston ever legally used when it doesn't fit the correct head?
It goes deeper than this though, Jim absolutely knew what the original and legal piston was, he even posted a photo of it here in 2013:
http://classracer.com/classforum/sho...64&postcount=2