I can't offer anything of help, but I can say that I'm experiencing the same thing. The first sending unit was way off, so I put another one in. This one too is way off. A full tank of gas reads 1/2 on the gauge. I took that one out and tried bending the float arm. Of course it's still way off. Once the body work gets going this summer I'll pull the tank out and go over it one more time. After that, I'll just deal with it I guess. Not that I go on many long distance road trips anyways I suppose.