Good used radiator (or just tanks)

[option B9]

  My friend picked up a real nice mostly original 65 GS this past summer. Unfortunately the non stock aluminum radiator exploded due to a stuck thermostat. So I would like to replace it with a stock unit. A decent set of tanks would be OK too, then I would have a 4 core installed. This GS does not have AC.

                                      Thanks    Tony