Reply to "Vapor Lock"

There is a vent hose coming off the top of the fuel tank on my '73 L. It can be viewed under the little black wing that also supports the engine screen. The vent has a tube on it running down in front of the tank. So, if you have such a vent on your Pantera gas tank, there should be no need for a ventilated gas cap.

When my Pantera was vapor locking, the phenolic gasket between the carb and manifold did the trick and stopped the vapor lock.

Now might be a good time to inspect the fuel pump, taking a systematic approach. If it's a mechanical fuel pump, some of them can be disassembled. Inside the mechanical fuel pump, there's a rubber diaphram to pulse back and forth, pumping the gas. It should be free of cracks, be pliable and have a good seal. I have an electric fuel pump, and I went ahead and just replaced it anyway, so as to eliminate that as any source of reliabilty issue in the near future.

Modern vehicles, with fuel injection, usually have two fuel pumps, one in the tank (primary pump) and one in-line, en route to the injections system (secondary fuel pump). When a car runs out of gas, the primary, in-the-tank fuel pump will over heat and cause the same symptoms you describe. That's why I mention the fuel pump as an item to attend to.