I’ve racked my brain (didn’t take very long = small brain. LOL!)
I have not been able to understand the noise.
Water pump has not been tested but it was new and turns freely by hand, so it passes my bench inspection.
Not a noisy fuel pump because it’s not making noise now on my other 283. It was pumping gas good enough to drive highway speeds all the way home the night I made the video of the noise.
Builder says bearings look fine. I assume he looked at both crank and rod bearings.
We will just have to wait and see.