69 Dart fuel system question
It's diagrammed right in the FSM. You can download one here:
http://www.forabodiesonly.com/mopar/showthread.php?t=132309&highlight=manual,+download
It runs down along the filler tube, down through a hole in the plastic? rubber? cover on the trunk floor and ends INSIDE the frame rail. That is, there's a hole in the top of the rear frame rail, it just pokes down in there
VERY important to have a tight seal around that floor gasket to keep fumes out.