Howdy new here and impressed with some of the knowledge. This is a KB190 piston from a 360. The motor has done next to no work maybe an hour running time and had spun a bearing. I've had the crank ground and also had the rods resized and have just noticed this? Is it from being knocked around on the way to the machine shop, being roughly handled some where or engine running damage? The engine is less that 10.5 :1 open chamber J heads and was running on methanol with around 36 deg ignition. There are two photo's attached
Cheers
Tony