GM-51092 is used to verify that the camshaft fuel pump lobe is at the base circle position before installing the high-pressure fuel pump on Gen V V6 & V8 engines. The fuel pump must be drawn into position evenly. If the fuel pump lobe is not on the base circle, the fuel pump push rod may be damaged. GM-51092 provides a visual indication that the camshaft is in the correct position for the pump to be installed correctly. GM-51092 installs into the fuel pump bore and indicates that the fuel pump may be installed when it is flush with the mounting surface of the manifold.