Hello,Unfortunately ,In 99% of all cases there is no fix a leak product that will work and in most cases it actually can cause other damage like pluging the radaitor and the heater core, the 4.3 has known issues with the intake gasket leaking as well as the head gaskets. The best way stop the leak is to do the repair properly.
I saw this demo on the Therma gasket repair yesterday and it looked very convincing. Thanks
Remember its like am infomercial. they sell product. I sure wouldnt use it my self. Eaither way , you are very welcome, thank you very much as well.