The problem is when you run the manufacturers suggested clearance. 84mm CP's call for 0.0035" which is way too tight for a motor making that much power which is probably what happened. On big power boosted engines I run a minimum of 0.0050-0.0055", they are a bit loud at idle but you got to have them that loose to make over 700whp. A shelf stock ARIAS piston will make 800whp easy with the right clearances built into them. Also the right stagger or piston ring end clearances helps.