Porky, you are correct that the original line hugged the frame and was attached to it with clips. It ran parallel to the brake line attached to the same frame rail.
Just in case you get frustrated with the line that you have, let me offer a suggestion tied to what Bartamos posted. Instead of using steel brake line, try nicopp. It is much easier to work with. I recently replaced the original steel fuel line on my '57 using nicopp. It was remarkably easy. Start at the fuel pump and work your way back. Mark, bend, test fit, repeat as you work your way to the back... and be patient. It took me less than an hour.
The longest straight length that I could find in the correct diameter was 74". I bought it at O'Reilly. The brand was Edelmann Copperhead. It worked fine, but get a piece a little longer (84") if you can find it. It will come flared with fittings at both ends. The fittings match the ones on the original fuel line, so one end connects easily to the fuel pump. Cut the fitting and flare off the other end. Once you have it installed and clipped in, attach it to the gas tank down tube with rubber fuel line and good clamps.
The nicopp makes the installation easy. If you get a piece long enough to start with, you can make the line out of single length of tubing without the need for a union.
Matt
