Started my 340, IT KNOCKS! fresh rebuild HELP!!

I'm thinking along the lines of 360Z28, but the other way. When you pull each plug wire, listen to see if the noise goes away. Narrows it down to a particular cyl. If there are any bad parts on that cyl, the noise will go away (or ease up) when the wire is off. Wrist pin, mainly.

360Z28: What are you looking for when the sound gets louder?