Yes, the pink is the gas gauge. I'm thinking you would use the body mounted wire because the body harness does not route the line to the bumper harness as does the ElCamino so it should be dead at that point. Same thing with the side marker lights, the wires are not routed to the bumper harness so use the body harness mounted lights and omit the lines in the bumper. Just pull the bulbs, grease the sockets, and tape them shut, you may want them down the line. Just make sure all the other wires match up color for color at the connector and you should be fine.
