Engine overheating

I noticed in your pictures that you do not have a fan shroud. Without a shroud, air will not be forced through the radiator and it absolutely WILL overheat when standing still; even if the radiator is fine. A shroud will force the air to flow through the radiator; not around it. You also need a hood to radiator seal. The car came with one, and they also help force air through the radiator.