Under flip top locking gas cap question? HELP!

[mellowguy]

I have a 73 challenger in the middle of restoration. I have several gas filler tubes one is out of my 73 and the other is out of I think a 70 or 71. I don't know how to tell the difference. With that said I have a 70-1 flip top upper cap I will be using. Also I will be running fuel injection and the fuel system should be vented (per EFI manufacture recommendations). Ok, I am thinking a shallow (to clear the fip top upper gas cap, locking, and VENTED) gas cap.  Any thoughts, suggestions, or part number recommendations? Thanks everybody.

[MEK-Dangerfield]

I'm not much help, but a 70 filler tube is vented. A 71 is not. The 70 tube has a line that ends in the right rear frame rail for ventilation.

[mellowguy]

MEK-dangerfield thanks for the reply. I was aware that in 1970 (non California car) Challengers had a 1/4 tube vent near the top of the gas filler tube. I was interested if there were any available (new or old)  locking gas caps that would clear the Flip top Challenger upper gas cap and BE A VENTED DESIGN. I have both 70 and 73 Challenger filler tubes but I can add a 1/4 tube vent to either, if necessary. I want to have enough venting and not collapse the gas tank, when I really stand on the throttle or take it to the drag strip. Any thoughts or suggestions?