Your best bet is to overclock in the BIOS...many GUI based tools ramp up your voltage higher than they need to be, resulting in higher temps. And just FYI...any 2500k or 2600k that you overclock over 4 ghz and closer to 4.5...you are going to see fairly higher temps, regardless. You'll need a more powerful cooling solution if you are wanting to see cooler temps at those clock speeds or higher, even if you address your airflow issues. What you are seeing is probably about right...maybe a little warm. If you used better fans in push/pull you might drop your temps 3-4C at load.