Oh my another 8/9800gt overheating thread.
Tbh, 73C under load is nothing for the gpu itself, but it might be overheating the rest of your system. My 8800gt idled at 75C/90+ load and ran games fine until the fan failed.
You might want to look at your overall system temps instead of just the graphics card. Buy a cheap pci extractor fan from newegg, they cost buttons and can really help to draw heat out of poorly ventilated systems.