Does anyone offer a 9/16-20 "female" inverted flare adapter, tee, etc? Or, can someone suggest adapting a 9/16-20 inverted male withh a more common size that a 3/8-24 brake line can be attached. I'm open to using AN fitting too.

Just to clarify, this the 9/16-20 inverted flare, male fitting that is found on the "front", rear brake line which attaches to "rear-out" on the proportionate valve on a '73 Challenger with disc/drums).

Step two is to cut off the 9/16-20 nut & inverted flare and add another tube nut and then reflare the line. Just want to make sure that I'm not overlooking something especially since I'm dealing with a stainless steel line.