The fuel level sender (often mistakenly called a fuel meter body) in a 1997 Silverado is a component located inside the fuel tank. It's not a separate "body" in the way a carburetor might be, but rather a unit that contains a float and a potentiometer (or sometimes a variable resistor). The float moves with the fuel level, changing the resistance in the potentiometer, which sends a signal to the instrument cluster to display the fuel gauge reading.
There isn't a single "fuel meter body" part number, as the entire assembly usually involves the sender unit, float, and possibly a sending unit mounting gasket. You'd need to find the part number based on your specific truck's fuel tank configuration and engine. A parts store (auto parts store websites or the dealer) would be able to look up the correct part number using your VIN.
