Overheating Big Block

[mprat]

Well I just finished the test. And it says it does not have a blown head gasket. Shows there are no combustion going into the radiator. That is one big relief and eliminates one big answer but still does not answer why the pressure and overheating. If you want to watch how this is done, go to "how to tell if your head gasket is blown" on the internet and there is a YouTube video you can watch. Now what could be causing the excessive pressure, and overheating????????