How do I stop vapor lock?

67Dart273 said
Not sure if you are referring to the earlier 69 type vent or the newer "up front" which interconnects with the carbon can system

The old system has no valve. The cap is completely sealed, and the vent is simply an open 1/4" tube that goes down and ends, open end, inside the rear frame rail. The only possible way it could dribble is if the tank is EXTREMELY full, "up into" the filler tube, and either expands enough, or is parked on a side hill so that fuel is forced out. Even so, only a cup or two will drain, after it gets down below that level it can no longer do so.

If you look through those manuals, it's in there. Again, some is in the fuel system, and some is in the emissions section in the back of the book

I looked through the fuel tank section of the manual from 69. I do have the 69 style. It did say to vent into atmosphere. I'm just thinkin' it would be safer to place the exit of the vent tube in the center of the car near the front of the fuel tank, but lower than the fuel tank, between the fuel tank and the rear-end, so that it is as far as possible from any backfires. My exhaust exits right behind the back wheels, I mean right behind the back wheels, so if it were to come out the grommet and exit into the frame rail, it would be extremely close to my exhaust. It is dual.