Two battery side-post extensions that were too long, bolt cutters and file later, I have solved nothing. I still have alternator whine in my radio. I’m going to have to try moving my positve lead from the accessory bus to the battery directly.
Later… I redid the positive side. It’s a big improvement, but not a completely solved problem. There’s still a tinge of high pitched whine over 2500 RPM. “That’s good enough” but I suspect I’ll keep trying to eliminate it.