[litew8]

I'm not sure. Is there a large float inside of the tank? Fill it up 3/4 of the way and shake the cab back and forth (give it hell) and see if anything changes. You can also search these threads with the Google box above. Just tick the 67-72 radio button before clicking search (Google). Quick search found this: http://67-72chevytrucks.com/vboard/s...d.php?t=456772