your going to want a forged piston everyday of the week, oem is cast and your pushing your lock with boost. i would recomend wiseco pistons, there spendy but worth it 10 times out of 9. Find a dealler for western power sports and go there. if your in the portland oregon area/ vancouver washington area let me know and i can hook you up with a good dealer.
I agree, you would have taken out forged as well, maybe not cracked, but would have been melted above the top ring. I like wiescos but the stock pistons have proven themselves over and over in turbo apps.See the missing pieces between rings.......these are signs of detonation.