Some of my 5 gallon plastic gas cans happen to be the same size and
threads of a briggs & stratton lawnmower engine. I swapped them by
accident and the sealed cap killed the engine pretty quick.

I have thouggt about replacing my bad caps, 2 lost one cracked with
those lawnmower gas tank caps. Although they have a automated vent for
high pressure. I have never been fond of swollen gasoline cans that
look like a over filled balloon