Hello all. I recently had to replace my Avanti's fuel tank vent tube because I could smell gas coming out of the pores of the rubber. I believe it was original to the car. Certainly the sending unit was, which I replaced, and its gasket was nearly dust. However after all this I was still getting a strong gas odor from the car. I crawled around sniffing everything I could find and discovered that the smell was most notably coming from the end of the vent tube under the car!
I thought that since gas fumes are heavier than air that the figure 8 arrangement would have kept gas fumes from exiting the hose. I would have liked to have run the hose up in the c-pillar like the factory one, but there is no practical way to access that area. As a test I used a piece of a Home Depot bag and a rubber band to cap off the bottom of the hose, and the next day the gas smell in my shop was almost gone! But obviously that isn't a solution...so what is?
p.s. I am using a new Avanti fuel cap, I think I had bought it from Studebaker Intl but it's been 6-7 years. If memory serves it is a vented cap.