Dart gas cap confusion

[Brooks James]

I bought the grey cap , was advertised to fit my 70 Dart, NO GO.
As you can see the attaching points are deeper in the filler neck with the orange cap.
The orange cap will allow air in but not out. I have a CA car with the 4 nipples on the gas tank that go to a fume capturer, which I will be removin. Should I drill the orange cap so that it can have air coming in and out ??

BTW, WHAT YR(S) DOES THE GREY CAP FIT ?

 

[CFD244]

Compliments of @Oldmanmopar Thanks Steve!

 

[Professor Fate]

DON'T drill your cap unless you want gas dribbling down your quarter panel.
Use one of the tank nipples and plumb it to a rollover valve mounted higher than the tank. This will allow the tank to vent and not leak gas.