Sure, your pulley ratio is 1:1, which is 30% less than what the factory did for an AC car. Which means your fan speed is 30% less, and your pump speed is 30% less than what the factory used. So it's very possible you aren't moving enough air OR water, especially if you're using a standard water pump.
I would look for a smaller water pump pulley. Or a larger crank pulley. You could also use a high volume water pump, because if you're using a standard pump with that 1:1 ratio you're not even moving the same amount of water as a factory non-ac car (same-ish ratio, but a HV pump). Although the HV pump wouldn't improve your fan speed like going to the smaller pulley would.
