Drilled and tapped to 1/8. Something to note: i didnt drill the full length of the diameter of the tap. It is maybe 1/8, 1/4, and whatever the drill size is for the 1/8 npt. It does have continuity, but i am not able to pressure test until my lines show up. I am fairly confident it will work, and if i have to buy another MC anyway maybe i can help the community out while i am at it.