Show me stock 1974 Dodge Dart (sport) gas tank vent routing

67Dart273 said
MAKE SURE if you do a rear "up and down" and the opening low as pictured above, that you TEST it for SIPHON. Determine the low side if any, fill it close "to the top" of the filler and then park it "vent low" and see if it siphons on a hot day.

The beauty of the 69/ earlier vents is that they were vented way up high in the filler, which formed a "siphon break." The only way they would siphon (a little) is if they were filled up (or heat expanded up) into the neck, above the vent connection. Then they would only siphon ?? a quart, whatever ?? until the level got below the vent line in the filler, and "break" the siphon.

I do understand what you’re saying but the top of the loop under the package tray is 6-7 inches higher than the very highest point of the filler neck making the “siphon break” you speak of even higher than the 69 style you speak of. The portion that drains into the frame rail only goes into it about an inch and half, which is still higher than the tank itself by about 3”. I don’t ever like to say ‘never’ but I’m pretty darn sure this could ‘never’ siphon.. even if it did the vent tube inside the tank is at the very top of the tank, how much could it ever siphon - a couple once’s until it sucks air? I think the angle the car would have to be parked with the right side low to get it to start a siphon would have to be pretty severe..?

all this said, I never jam as much gas in my cars as I can so I don’t think this should happen to me anyway, but I’ll keep an eye on it and watch. Thanks.

ps. All this said, how in earth did the factory set up with a vapour canister up front mounted pretty low no have siphon issues?