I am using a simple Filler neck from a 68 mustang with a 68 Mustang vented filler cap. I will not have any other venting. My body has been modified to fill from the rear fender not the rear deck, so my tank is in the trunk floor not the trunk shelf. You see, the fuel caps used back in the day used a two way valve in them that allowed air in and vapor out also. If you wanted to use a more modern set-up, you could have a tank vent but then you need to add a liquid discrimnator valve, canister with hoses that lead back to the carb for vapor re-intro into carb base etc etc. I wanted to keep it simple and avoid all that. A good fuel tank that does not leak is the most important part of the system.
