Depending on what you mean by "Much fuel", I would agree. I have taken a unit out of my 69 Barracuda FB twice with the tank still in the car. Once to replace the sending unit with an aftermarket unit from Classic Industries (it works fine; maybe I was lucky), and once to fix a leak gasket. I got it down to about a quarter of a tank each time and had no problems. If it was just slightly under half, I can see having a problem.
