Gas cap - Vented or Not
Does your gas tank have a vent built into the top of it? Some have one, some have a few, some have none. If none you need a vented cap. I bet you have a vent tube at the tank, they are typically above the sender.
Here is a 71 to 76 tank.
Gas Tank (16 Gallon, w/ 1 Front Vent Line) - 71-76 Dodge Plymouth A-Body Gas Tanks | AMD 890-1071
Does your gas tank have a vent built into the top of it? Some have one, some have a few, some have none. If none you need a vented cap. I bet you have a vent tube at the tank, they are typically above the sender.
Here is a 71 to 76 tank.
Gas Tank (16 Gallon, w/ 1 Front Vent Line) - 71-76 Dodge Plymouth A-Body Gas Tanks | AMD 890-1071