Either way works, the way i see it, as long as the float needle valve closes at the correct time whats the difference? I personally like to correct the level by the "contact arm" but everytime i read or come across adjusting the floats it says to bend the "tangs". Personal pref. or some reason behind it you got me. I also dont ever measure distance, i just make sure the needle valve closes before the fuel reaches the overflow... (Mating surface/Mold line are parallel on both floats and float looks level [not too low/not too high] when needle valve is closed)