when you pickup a MC you might grab those MC port brass plugs & see if your current MC hold pressure (light pedal pressure & stomp it) & if it ain't the current MC then you can return the new/rebuilt one & while you are there likely they will let you use the MC in the box to get the correct fittings (1/2-18 or 1/2-20 or 9/16-18 or 9/16-20 iirc).