The term Chevrolet fuel sending unit is a new way of describing the part that transfers fuel from the tank to the engine. On many models they use a fuel sending unit that also contains a fuel pump. On others they just have a float and a sensor that sends the information to the fuel gauge along with a screen at its intake which prevents large debris from entering the fuel line. One thing all Chevrolets have in common is that they have a fuel sending unit in the gas tank of the vehicle. This is a specific part for each Chevrolet model which cannot be interchanged with many other models unless they have an identical gas tank and fuel gauge. The reason the fuel sending unit cannot be interchanged with parts for other models is that each one has specific positioning of the fuel lines along with the breather line or vent for the gas tank. The electronic sending unit to the fuel gauge also has a specific connection just for your model. To access the Chevrolet fuel sending unit, the gas tank has to be removed or lowered. The fuel sending unit is usually located on top of the tank in the middle. All of the fuel lines and wires must be removed before the tank can be taken from the Chevrolet and access to this part can be made. The main reason the fuel sending unit is replaced is because the float or sensor in the tank is no longer functioning and the driver cannot know how much fuel they have on board their car. On rare occasion the screen does become clogged. If that is the reason a new screen can be purchased and put in place to allow fluid to flow unrestricted again.