That's pressure vacuum cap, that's not a vent. Well it is a vent but it won't open until about 1 psi according to my factory service manual. I have one for a 71 and a 74. Both years vent the fuel tank through the line that goes up front, either to the charcol canister72-74? or to the breather on the valve cover like on my 71.

74

71

Last edited by Challenger 1; 04/03/12 05:09 PM.