Hopefully somebody can help diagnois a problem with my 68 FB Conv 350 that just started. My fuel guage just started registering all the way to the right of full (approx.3 o'clock ). Again this just started and I know that I have approx 1/2 of a tank of gas. Any ideas what can cause this...I did not find anything in the dianosis manual that sounded like this? Hope someone has run into this before.