Thanks for the info I honestly just grabbed a cleaning jag and it fit so I called it good.I did put the 2 sets of threads against each other and they did seem to mate very well. Maybe because the clean out screw has a round head on it and I used antiseize on it it seals better.
I also brought both screws to Ace hardware and they both seemed to fit the other threads equally well.
I also brought both screws to Ace hardware and they both seemed to fit the other threads equally well.