the needle swings widely, often below E. It rests at 1/4 tank when the truck is off. When i turn it on the needle starts to go crazy (mentioned above) Strangly though, when i fill the tank up it reads perfect down to about 7/8-3/4 tank then it goes haywire when it drops below that amount. The low fuel light still works fine tho.
any suggestions? thanks!

 

The fuel level sensors were a big problem on these trucks. It may just be the connectors are corded. There is a small write up in the FAQ about this issue.

 

Also theses trucks are know for bad floats, Had to replace my fuelpump to fix my gauge