A few pics of barracuda project.

Ok that answers my question, all make sense.
The lines are pretty darn hard to get inside the frame and fish them up and over the rear frame rails, and out in back, thru an existing "elongated hole," behind the tank .
I couldn`t get both lines in there, one was a *****, and it is braided s/s (ptfe) . With the up and over, the grommit going in and coming out of the frame, and being a short run where its straight laying in the connectors, I am not the least bit concerned about it , there will be no movement laying in there anyway. If it were a fuel drasgster , maybe. The other feed hose is out side the frame rails w/ adel clamps on it . I ran a hemi s/stocker type car for 14 yrs done that way, and it vibrated way more than this street car. It had a 785 lift solid roller in it. The inside frame deal was an after thot, when I switched to fuel inj. and needed a return. The original posters car being on a rotisserie, would be the ideal time to plan and execute all this , mine was pretty much on a finished car setting in the garage.
A long run as in an airplane , yes I can agree w/ you, but not in a 4 ft run.