Here is a strange one...

I put water in my B1 engine tonight and ran the electric water pump to purge air as it circulates.
Just as the pump sounded like it was building a little pressure, I noticed water on top of the valley plate (under the intake manifold).
After drying and repeating a couple times, I was able to isolate it to near the center bolt that secures the valley plate to the head.

Very strange... Anyone ever heard of B1 big block heads hitting water in any of those valley plate threaded bolt holes?
Does that larger round hole above the center connect to water? I am not sure right now if the RB intake spacers cover that.
But the intake gaskets I am using basically sit on top of the valley plate (I cut them to fit) above the valley plate. So it should be covered.

I removed the bolt, and dried it with compressed air. Put RTV on the bolt threads and reinstalled. After curing overnight, I will try running the water pump again tomorrow.