Having just replaced the entire fuel system on my 57 T-Bird, I can tell you that the two piece fule line from the tank to the flexible line was a pain in the butt. We may not have been as patient as we could have been, but getting the line from the tank, snaked up and around to the frame under the driver's door, just wasn't happening. Since we had a couple of fittings from the line we took off, we decided to turn the two piece line into a three piece line. Thanks to a couple of newly created flair fittings, the new line went in much easier. I'm still not a fan of flair fittings, as in my personal experience, they are prone to leak until they get tightened more that you think they should need to be. Usually at 1:15 in the morning with a puddle of gas on the garage floor (Don't ask me how I know this).
If you are looking for concourse correct, you will have your work cut out for you, when you try and feed the second part of the line, back to the tank.
Good luck.
Bill Poland312 V8 - in a 1957 T-Bird
Baltimore, Maryland