URGENT! Gas cap for 71 Duster

I have seen some 72 up caps on 71 cars . 72 and newer caps fit on the tubes that screw on to the outside of the quarter. 71 and back the the screws go through the quarter and thread into the tube. Tube flange is on the inside of the quarter.

Another words the difference is the tube and the way it is fastened. 72 up cars the screws thread into the quarter. 71 and older the screws thread into the tube. I believe some tubes could have been changed years ago if the 71 caps were lost. 71 caps have not been available for a long time. Lose your cap you needed a different tube for a proper seal.

I just acquired a 70 tube and cap for my 71 duster. 70 duster is the only sport body style that has a vented tube. One year only. This tube will accept caps from 67 -70 and the caps are not vented. These 70 tubes fit the 71's and still fasten to the quarter correctly. Also allow for the hoses for the vent/Impact collision protection on the 71 to be plugged.

I prefer this early style over the 71. It Allows the tube to be fastened correctly and eliminates the chance of the fuel being forced into the headliner of the car on impact.

A 72 and newer can also be used but if installed on the outside it moves the cap out past flush from the quarter a bit do to the different indent in the quarter on pre 72 cars.

All replacement quarters I have seen have the same intent as 72 and newer. Change the quarter. Change the tube. Or live with the cap not flush with the quarter. Just some experience I have had with gas caps over the years.

As stated the best thing I found is use a vented tube. And fill all vent hoses to plug them in the system. They will no longer be needed. Open vents were eliminated in 71 to contain fuel in the car on collisions. 71 was one of Mopars saftey screw ups the was changed for 72 due to liability issues.

Many still call this a vent system as per the manuals. First vent system I ever saw with a tube that has a cap facing the headliner with several lines going to it. Mine will be there for appearance only. If you leave it in take the fuse out of the dome light.