I swear I read on several forums that Dex-Cool was the stuff to use with cooling ststems that contain a lot of aluminum as it helps prevent electrolysis. Having a cooling system with a lot of different metals in it... aluminum radiator and water pump, steel water pump impeller, iron block/head (hopefully an aluminum head eventually) and a brass/copper heater core, electrolysis is really a worry. And Dex-Cool is supposed to last longer than regular antifreeze.

Today when I searched all I found about Dex-Cool were links to the class action lawsuit saying it destroys intake manifold gaskets. Luckily on this particular engine the coolant goes nowhere near the intake gasket, but I am worried about it eating the head gasket. I wonder if all this class action business is just a bunch of goobers who believe GM when GM tells them they can go 160k without flushing the coolant.

Before I add the heater core I might go ahead and flush it a few times and go back to regular green antifreeze.