ohh I get it lol!! So you just stick the brass ferrule on the fuel rail(aka TUBE) and tighten the blue and red together, then that smooshes the ferrule down tight on the end...i never knew you could do that.Soooooo now you have two -6an fittings hanging off your fuel rail. Well, i know on my tbi truck, the female fuel line ends under the hood are *NOT* AN fittings. They are FUEL line fittings, since they hold the silly o-ring and have a counterbore in the fitting for said o-ring. the -AN fitting have that bigol' taper on the end, and will *NOT* thread into a FUEL fitting.