1972 Dodge Challenger fuel tank question

[Darcyh]

I have a 1972 Dodge Challenger and I have to replace the quarter panels. My body man was asking if I need to keep the 4 vapor lines going into the tube in the trunk. I have changed the carb to a FiTech EFI and I am using the line to the charcoal canister as a return line for the EFI. I am not using the charcoal canister anymore. My question is: do I need the Vapor separator and the vent lines? I have a 340 in the car with EFI.

[Cuda Cody]

Welcome to the forum @Darcyh   

There's a few ways you can do it.  Are you planning to use the original fuel tank?

[Darcyh]

I plan on using the tank that is in place now. I don't think it is original. I might go to an in-tank fuel pump later on. I have an external electric pump mounted by the tank now for the EFI. I have since talked to a Mopar guru who says the vapor separator was used for pollution control and I don't need it anymore. He said I could just plug the vents off for now.

[Chryco Psycho]

You need 1 vent , so either a vented cap instead of a seal one or 1 line can be left open but it needs to be higher than the tank so fuel does get out , with no vent you can get a vacuum inside the fuel tank causing fuel supply issues

[Darcyh]

Do you mean a vented gas cap?

[RUNCHARGER]

Yes he does. The tank has to be vented somehow.

[Darcyh]

Thanks, another question, I have a flip-top gas cap on now. My question is do I need a gas cap (vented) underneath the flip-top?

[RUNCHARGER]

Yes you do, 1970 style, however the 70 cap is different in the nub area that secures it to the filler neck.