Working on a project 460 utility and ran into something odd, was wondering if someone could give me a bid of insight on this. Recently replaced con rod bearings and rings, put everything back together and noticed i had a substantial knock. Pulled the pan off, plastic gauged all connecting rod bearings and mains and couldn't find anything out of the ordinary. Pulled the head off and found a shiny spot on #3 piston and also a corresponding spot on the head that was shiny. Assuming that the piston is hitting the head at this spot. It's on the high spot on the piston between where the pockets are for the valves.
Has anyone out there heard of this happening before and what was the cause?