Yea I did surface the block and head before installing the head-gasket and I am 100% sure that it was installed properly. I know cometic is a great brand I have used them before with no problems; however, until I take it apart I can only guess at what went wrong. I do know that it did blow into a coolant passage because there is air coming out of the overflow tank and the tank overflows when I really get on the throttle. Thanks for the information though.