Its a blessing? Weird debree has found its way into peoples motors and completely destroyed them for many years, horror stories they are. I cant think of there that would have came from or been apart of. Perhaps a peice of missed slag when the motor was manufactured? Reguardless since the motor is still running good I would see it as a blessing that it didnt find its way into my valvetrain or destroy the motor in one way or another. And if it was apart of somthing important like a rod pin im sure you would be having issues by now. Lucky you.