What fitting is this?

Dana67Dart said
As I understand this was factory

View attachment 1715750858

Yes. This is what I need. Might have to start scouring eBay for used mc.

It's not npt. I pulled out the residual valve on that port this morning, there's a brass inverted flare seat in there.

Really appreciate the help y'all. I gotta find one of those adapters now.