The cooling system really deserves an article all it’s own. It’s the reason this head gasket blew in the first place. The stock thermostat should definitely be replaced with the cooler-opening Motorad 180-degree version. It only keeps the engine cooler by a few degrees, but this engine needs that few degrees to not trip dash lights. Also, no Dexcool! Dexcool, along with air bubbles or other coolants mixed in, can break down aluminum. Get rid of it. A later photo illustrates the dissolved block water jacket ports. Flush the engine well, and replace coolant with standard green ethylene glycol antifreeze (50 percent), plus a new lower temp (180 degree) thermostat, a new radiator, and new water pump. This is all very important stuff.