Ouch!! No good. IMO go with new Forged pistons. The Hypereutectic's are ok but in no way are they as tough as a forged piston. Hypereutectic's do not take to well to boost or N2O.
Looking at the plugs and valves shows nothing but a lean color of white to me. The intake valves would be that color too if it wasn't for the amount of fuel flowing through. I would look into it being lean more then you think!! Upon re-assembly maybe it's time for some baseline dyno pulls with a/f?!?!?!
