did u do a compression test.
I had a broken piston that was considerably worse than that and I didn't get any overheating issues. Are you sure the engine doesn't have other problems?
time for forged ones
did you figure out the reason why it cracked in the first place? how much boost are you running and what size injectors?
Do you think détonation or alot power make cracked ring land!?
Overheating has nothing to do with broken pistons! Bad engine build between the forged and non forged is what makes it overheat.
Did you mix up the cam caps? They are factory marked.