I don't have a 71 relay to give you a definitive answer. The unknown factor is the +12vdc coming from the headlight dimmer switch. On the 71, the road lamps are disabled when you turn on the high beams. I don't know if the +12vdc from the dimmer switch supplies power to the road lamps or the relay.
Maybe someone with a 71 relay can map out the terminal connections and describe what they do and how they do it?