It puts the highest point in the system your radiator cap so it should "burp" itself in theory. With all the threads on LS engines having the air pockets I have never said much about this. My 97 vortec 5.7 has a rear radiator. I put the funnel on the radiator and let it idle for about 10 minutes. I have never had a problem. At work I put it on and let it idle until the coolant in the funnel gets warm. Never had a car come back for an air pocket.