Ram Van Overheating

I have a 2000 Dodge Ram van 3500 15 passenger, 5.9 liter engine. It has a new radiator, fan clutch, water pump, thermostat. The compression checks out fine. I am having problems with it over heating. It will do fine without a load on it, but if I am going up hill, have the AC on, or even sitting in traffic, the temp keeps climbing until i have to pull over. I have seen where people put electric fans on and that resolves that problem. Has anyone had similar problems, tried an electric fan, any success?
thank you

If you have A/C it should be a three row radiator. Many people install two row radiator not knowing the difference. When it's cold, open the radiator cap and see if there are 2 or 3 rows in there. If it's only two then your problem is a wrong radiator. That 3rd row gives you about 50% more cooling power which is needed when the A/C is on.

We have explored that option, but have not been able to find a 3 row that goes in this vehicle. They say that the 2 row is the biggest available. Any ideas on where to get one?