UPDATE:
This is the build that Never ends,
Yes, it goes on and on my friends!
When I started building it, not knowing what it was, but I'll continue building forever just because......Some of GM's parts have poor quality control.....
Today, I fixed the same coolant leak for the 3rd time. I've replaced the water outlet and the heater house and I've finally discovered the issue. The heater hose that I bought had a clamp on it from the factory. I re-used that clamp after replacing both the water outlet and the hose. I carefully examined the clamp today and realized the one edge of the clamp was razor sharp! It would hold coolant until the rubber expanded and then the clamp would cut into the hose.
I went to my local GM dealership today and bought an older revision of the hose without a clamp and then installed it with a worm gear clamp.
Currently I'm waiting on Amazon for coolant.