360 Plug help

So, are those bleed holes threaded? What is the history of the carb? I had a mighty demon 825 that worked well after pulling it apart and cleaning all the metal slivers out of it. It was a new carb. Quality control sucked at demon for a good bit. All my screw in air bleed slots were stripped also. You really need to know what the vacuum reading is to determine what power valve to start with.