Chris decided to use an internal fuel pump. To do this, he modified an original ´73 sending unit by replacing the 1/4-inch return line with a 5/16-inch line. A fuel-pump power wire was installed in the sending unit. Any pre-´77 GM fuel-tank sending unit has a removable power lead connector. A hole must be drilled to install the connector for pump power. Solder the ground wire to the sending unit and make sure that the sending unit has an external ground to the frame. The fuel-pump power and ground wires must be fuel resistant, and can be obtained from any ´87 or newer GM product located in a salvage yard.