the ihs is copper cored so the heat spreads out evenly on it so you would need to cover the entire ihs with thermal past. If you do remove your ihs and want to put it back on (for addaded core pertection) i would highly suggest lapping the ihs and putting as5 on the core and removing amd standerd crap that is inbetween the ihs and core. lap the ihs down until teh copper shows and you should be seeing better temps
			
			
				
		
			