Question for Ford Techs

[FED 387]

My 2000 goes to a higher level than when I parked it UNLESS I park on a level spot--either reads more or less depending whether it is nose up or tail up---mine takes a coupla minutes or miles to register what is really in the tank---also will do the samething if I put fuel in while it is running takes a bit to register what is really in there--If ya turn the engine off and then back on it will register immediately fuel level--- my 2001 gas truck makes no difference goes to actual level immediately no matter which way I have it parked--comp