My gtx460 768mb sits around 30-35 idle and rarely gets higher than 60 while playing games, even when its OCed to 850mhz. The fan ramps up to ensure that the card stays at 60%. . I have manually set the points for fan operation but the auto control seems to be doing a quieter job.
I'm guessing that your fan speed is not ramping up as fast as it could be, probably because of a software fan controller. You can probably change the fan speed settings in the utility that came with your graphics card. Also, CPUID shows me my fan speed %.
But 74 isn't too bad. You would be fine leaving it at that temp. But it could be lowered by speeding up the fan.
I should note that I put a 5 inch fan (not sure the mm size because its scratched off) that...