On my '97 the biggest improvement was to replace the factory steel lines with 3/8" ID hose. The factory lines are 11/32" OD and have crush bends in them. Plus I changed out the factory fittings with brass hose barbs drilled out to 7/16" ID. I also use a GEN 2 ATX cooler.
This keeps the temps down under the harshest of conditions. Much better than when I was running three coolers at one time. I also have the factory radiator cooler disconnected. In the winter I do have to cover part of the ATX cooler to get the temps up.