I had to replace the brake lines on my 61 which may be similar to a 64. I had to deform, tweak, the line where it goes over the frame midway on the chassis but I was able to tweak it back to preformed shape pretty well afterwords. I was going to do the same with the fuel line but there was one place at the front cowl body mount where there was a clamp securing it to the frame if I remember right and it couldn't be gotten to with the body in place so I gave up and just flushed the original line well and went with it.
Hey lgh 1157. I'm the guy that sold you the door glass for your 64' To answer your question, 'No". I tried on my 64' and ended up cutting the new line in two places. The first was just under the driver's side foot. I allowed the line to make the turn along the frame. My reason for this is the bends the line makes under the steering box. There is a clamp just behind the box that can be a bear. However, I loosened the box to install that part of the line. Worked out ok." note: be sure to flare the line/s before hand and before final install. don't ask me why, LOL! " I then used brass unionsto re-connect line. My second cut was after the line crossed back over the frame just ahead of the spring perch. Yes it was a pain but at that point better than lifting the body as I did not have that option. That's how I did it. Hope it goes well for you no matter which option you use. Don ( Ragan64)