I just got finished reassembling my engine (ford 223 straight 6) and im hearing this weird knock. It doesn’t start right away, and it only starts when the car has been running for a little bit and the noises are intermittent. I checked the cylinders through the spark plug hole to make sure I didn’t drop anything in there and I came up with nothing, I don’t think it’s a bent push rod. Does anyone have any suggestions?