340 J heads fs/ft 2.02 valve
Somethings wrong. Those numbers aren't for J heads (the last three numbers on a J head is 915), and there should be a J next to the spark plug holes, which there isn't. Those are late model smog heads (587). Stock they would have had 1.88 valves, did you have them cut for 2.02s?
Post a picture of the combustion chamber side of the head, of the full head, not just one chamber. Maybe I'm wrong.