1969 gas tank and sending unit

[697498chevy]

Finally got my old truck back together today . Had to replace my tank and sending unit . Had to enlarge several of the tank mounting holes so the filler neck was centered in the cab hole . Old sending unit was rusted and float had a hole in it . No wonder the gauge wasn't working . Took 6 gallons of gas before the gauge needle moved off empty . Wonder if anyone else has had the same experience ? Also wonder if ethanol gas caused any of this ?

[El Dorado Jim]

ethanol gas is really screwing things up...