Gas tank hook up 71demon

Well if you hook the tank line INTO the filler neck there is no vent. NONE. Maybe I misunderstand.........is the filler neck vented as per the 69/ earlier cars? If so, just plug the tank vapor line and done.

It's as I tried to explain earlier. You need to read the shop manuals through those years and compare them to the tank, and be CERTAIN which tank setup you have. Some of them have an internal vapor separator inside the tank, and some (earlier) require the long vapor separator that sits up inside the trunk. The earlier cars withOUT vapor controls have no such anything, originally, and they have the vent line welded into the top of the filler neck.

1..If you have the pre--vapor control tank (and I guess you don't) the only real practical option is the traditional vent out of the top of the filler neck, look up a 69 Dart/ Valiant shop manual

2...The start of vapor controls used the vapor separator, which connected several lines from the tank to the separator, and the line "up front" which IS the vent. There is no practical way that I'm aware of to get this vent to work "at the rear" because it must end "high" (like top of the engine bay) and it will siphon sometimes

3....The later versions had the vapor separator in the tank and this is even worse. Again you must get the vent line HIGH or it will spill and siphon. Again I know of no practical way to deal with this "at the rear" Where are you going to end it? I "guess" you could run it up high and out the upper corner of the car, but "if" it ever pukes, it will ruin paint. If you run it back down low, it will siphon.

THIS IS WAY ladies and gents, I recommend duplicating the 69/ earlier vent. It's simple. It has no bad tricks. And it works