This photo shows a failed gasket. There is a split in the material right next to my finger
The area at the top is the part that surrounds the water jacket, visible on the left side of the frame below. These V8 motors have coolant flowing into the head at the front and rear of the block, through the tall narrow passages. There is no from from block to head for the middle cylinders; hence you can only have a head gasket coolant failure on an end cylinder.
The picture below shows how the coolant turned to steam and scoured the interior of the cylinder. That steam cleaning is visible using a borescope; it's a positive means of identifying internal failure through the spark plug holes. If you see that telltale on an end cylinder it may be a head gasket or a block failure. In a middle cylinder, it's block failure for sure.
One other thing this image shows is how the block became slightly eroded in the area of the leak. If this engine were fixed by simply slapping on a gasket it would probably fail again. The cure would be to deck the block, or fit a top hat liner. Both those options involve total overhaul, though, so some would go for a used motor instead.
This photo shows a middle cylinder for comparison. The effect of coolant scouring is obvious now.