Have you considered that you may have the wrong water pump? Later models (those with the serpentine belt) use a reverse rotation pump. Consider also: Has a previous owner (or repair shop) put the wrong fan on your truck? I discovered that, on a 95 F150 I had bought, it had the older non-reverse rotation fan on it. While doing some other work on the truck several months ago, after parking it & leaving it idle in the drive that warm air was issuing forth from the grill: The fan was blowing forward! After changing the fan & clutch assembly the truck started cooling properly and the AC continued to cool even after coming to a stop while in traffic.

Also, when the radiator was replaced did it get the heavier two row type or the lighter single row?

dn.