I think by number of "connectors" you mean the number of terminals that go to the studs on the back of the alternator? On the '70 standard (alternator light, no gauge) alternator harness I have there are three terminals, the third I would think is for the Stator connection and this is what makes the alternator light work. I do not have a '70 alternator harness for a car with gauges, like XR7 or Eliminator, but on my '69 XR7, there are only two connections because there is no alternator light and charging is indicated by an ammeter whose signal is developed across a shunt in the charging circuit.
So, since you have an ammeter (I have that right, don't I? Eliminators have XR7 style gauges?), I would say you would want to use the alternator harness with two terminals on the alternator connector.
Kinda anti-climatic at this point, but if any additional confirmation is needed, I just checked my '70 (428) Eliminator, and it has two terminal connections, in a molded fitting, on the back of the alternator.