Possible to replace the stock fan with another fan?

Hi @wforwipeout

What is the model number of the Noctura fan?

You may be able to replace it if it as the same specifications as the original i.e. dimensions, accommodates the heat sink pipe that is attached to it, has the same voltage/current rating (5V/0.5A) and the same specifications for the speed and temp sensors built into the fan. The airflow rating (3CFM) may not be that important as long as it is not less as this would mean that the fan might have to work harder than it should

If the specifications aren't the same then you may run into cooling problems as the motherboard's fan motor, speed and temperature control circuits were all designed using the above specifications.

Here's the service manual for the model. Go to p.20 (of 44) to view the procedure to remove/replace the fan, to see what it looks like