arly Datsun L-series used dual point distributers to comply with smog,unlike mallory dual points, Datsun only runs on one set at at time.
Doesnt matter which connection you use. The timing is about 5 degrees apart between the 2 sets.
Simplified: hook to whichever terminal you prefer, just check the timing when you are done.
I was a Datsun tech back in the day,Am glad to help with any questions.
Vaughn