I'm not sure what part is in question here either. A 69 Dart doesn't use a hose, the filler is a rigid tube that goes from the fender to the tank. There is a flat gasket that goes at the filler neck to fender junction, and there is a donut-looking seal at the tank to hold the filler tube in place and keep it from leaking. There is a flat rubber seal that goes over the tube to close up the hole in the trunk where the tube passes through. The flat rubber seal is shown here, the top filler seal is out of sight behind the mounting hardware, and the tank seal is underneath the trunk pan. I think we need more info.
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