So here it is mostly done. The small diameter filler goes through a hole in the frame rail behind the shackle. That way it goes into the tank at the top rather than half way up the side. The capless deal is bulky so the actual pipe isn't very long. To avoid any cutting the filler sits at a downward angle to the quarter and I used a piece of ABS plumbing drain glued on to adapt that angle. I made a filler door out of a cut down 2010 F150 plastic one. Made a hinge from a hardware store one since there is a little over 1/4" depth to work with and no late model cars have anything compact enough. Just need to gap the door and clean up the hinge welds.
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