Gas syphoning out the vent/tank problems

Someplace, over at slantsix.org? There is an article on the early vents. The Barracudas (is that what you have??) Are somewhat different than the "trunked" cars

Is it possible the vent has been re-worked? The way the stock Darts / Valiants are built, it would be near impossible to spit, unless the tank is absolutely full up in the filler neck, and the inverted U of the vent is to break siphon

WHEN YOU POSE A QUESTION, please post year make and model
My bad, it's been a while

1965 Barracuda, running a 318 the previous owner put in.

The vent to me looks original unless he ran something different inside the filler tube, but I can't imagine that.

When it happened, I was able to stop it by plugging the vent tube with my finger, so I know it is coming from there and not a leak.

20230423_185023.jpg

20230423_184404.jpg

20230423_184811.jpg

20230423_184722.jpg

20230423_184452.jpg