[ElmoPerkins]

Yep. #6 is where the leak is coming from most likely. I had to chase mine down recently. It leaks behind the cowl and runs down the water drains making it look like the back of the engine. Replace #6 with new o rings and be careful when tightening it onto the heater core. I was lucky and didn’t need to replace the heater core after replacing #6. Hope this helps.