Originally Posted by NISR20MO

Your thermostat is what determines the temperature your engine runs at. If you took the thermostat out, you are positive it is well bled, and you are still overheating then you have another problem. The temperature rating of your thermostat determines when it opens to cycle hot coolant out and cool coolant in. Your radiator upgrade provides more fluid volume which will take longer to over-heat due to having more fluid volume and thus more thermal mass. The triple pass arrangement ensures the coolant gets better/more exposure to the tubes as the cooling air is moving through the fins and you should have cooler coolant going into the engine. The car should run at the same temperature however. If it is still overheating you haven't fixed the causal problem.

I hope you also upgraded the radiator cap or at least replaced it. If it doesn't hold pressure, you will always boil coolant and overheat.