Thanks for joining the Processor community.
The stock fan heatsink will do just fine for your processor model. Did you run Prime95 with stock thermal paste? Did you get different temperature readings with stock thermal material?
If you need to order Intel thermal material, you can use our Web Ticketing system to do that.
Online warranty: Service Request Email
Check the following URL for some tips to prevent overheating: Processors — How Do I Know if My Computer is Overheating?
Allan.