Still haven't pulled the engine to do the full autopsy but I think the issue is related to just that #3 cylinder. I'm on the fence about my next move. Just replace the bad piston/rings (cylinder bore still looks good) or build something new?; Forged pistons/rods, stock cast stroke? Forged stroker? Hard to ignore the cost of a complete forged 408 stroker kit. Need to have the cylinder head checked out also. Not sure how bad that damage is.