It may or may not overheat again, the obvious are the radiator not blocked? overheating in traffic or at highway speeds? I rebuilt my '67 289 in my Galaxie, the radiator looked fine, I had it cleaned and tested, it was fine, I used a 160-degree thermostat, it was fine at highway speeds, but in traffic, it was getting to 210, never "overheated" but was spitting out coolant. It had no fan shroud, so I used a cardboard box to make a pattern for a shroud, then fiberglassed the cardboard, stayed cool in the heaviest traffic afterward.
So, I have no answer it's a "hands-on" thing.