It was the #8 Cylinder on both episodes. The block overheated from a coolant leak. But, unfortunately, with no gauges I have no idea what the temps got up to. I wasn't driving it at the time. It got hot enough to blow the spark plug porcelain out, loosen up a couple exhaust valve seats, weakened all the springs, severely scuffed the #8 and #6 pistons/cylinders and froze the rings.

Surprisingly, there was no head or block warpage.

I'm not sure what they could have done other than overheat the rods when the pistons were installed. Maybe they honed the small end and while they were at it, too much ?