In process of re-installing my gas tank......put in a 3/8" pickup that has a 1/4" return/vent tube built in to it, was planning to plug it since my tank has 4 other vents that go to a 'reservoir' type device that I guess went to some pollution 'thing' up front. Was planning to just put a 1/4' line on it to act as a vent and tie it off to the rear cross member. Question thou there is some air resistence in this reservoir device and is this normal or should it blow thru freely......whats in that thing? Also should the gas cap have a vent hole in it or does it seal tight?.........thx.....d