Got a suggestion? I recently installed a 33 gal. round tank from an Isuzu on my 1971
Dodge D300 flatbed. The Dodge has a 383ci V8 and a big 4 bbl. carb --and just loves Gas, as did all big blocks in the 1970's. The Dodge has the factory 18 gal?? IN CAB tank and after three sending units, I still don't have a gauge I can truck. So with the added aux. tank, I have more range than I need. The Isuzu tank had an outlet pipe, return line pipe and and air line (Diesel tank) . So I blocked the return line , plumbed the large outlet to an in cab 3 way switch, and rain a short section of fuel line hose from this outlet to a point higher than the tank. I am ASSUMING this is to allow air in to the tank as the fuel is used. The tank has a large , screw down "brass" cap which I assume is more-or-less air tight. FINALLY my question. What can I use at the end of the "air" line to keep some critter from plugging the hole with a nest or whatever?? Thanks R
Life  is like a roll of toilet paper the closer  you get to the end, the faster it goes!  Enjoy each day.