most e bodies I have seen have 2 horns but the mounting position changes year to year , 70 was on the right inner fender & there should be 2 threaded holes & 2 smaller holes for the locating tab near them , your wiring should have 3 wires from the alt , two green / red for the horns & a brown for the washer pump . Not sure if 71 had them mounted in he same place .