Fuel injection fittings

[kwmech]

Looking for a not so common part. I am doing the plumbing on a fuel injection system and running steel lines down the frame rail. What I am looking for is the steel nut that pushes on the steel line into an O-Ring flare. The nut is similar to an inverted flare, but the threads are metric and the first 2 threads are not there so the O ring will crush down some. All I am getting is all the russel or earls conversion stuff to all the Army Navy fittings. There are 'repair' lines available, but they are only about 9 inches long. I need just the fittings that go on the steel line, then I can flare them to the o ring style

[mongocanfly]

Pics of what your looking for? Sounds similar to some hydraulic fittings I've seen