looks like an oil problem.

Does that piston have the same marks on the other side of it not in the picture? If so that is called 4 corner scoring and its from being overheated. Not only from the cooling system but from oil or piston being overheated.

 

can't figure out why it was starved for oil. it was full when we drained the oil, there weren't metal shavings in the pan nor in the filter but there was bearing material in the lifter valley and the heads.

it was a high mileage engine and I didn't think it would last a whole lot longer. When I picked the car up 4+ years ago I wasn't very kind to it...