The 138B, all of which were short bodied, never did the South Pacific route. That was introduced when we got the 338s.
Original routing from Dec 65 was Sydney Nandi Papeete Acapulco Mexico City Bermuda London. Later Auckland replaced Nandi. Sydney crews operated to Mexico City where the London based crews took over. A weeks slip in Tahiti was hard to take.
Tahitia - Acapulco was usually around 8 hours. Nothing much between the two so hard work for the nav. Extra oxygen fitted to enable cruise at, I seem to remember, 18000ft if there was decompression at ETP.