Well, I struggled through the process of switching out the header gaskets.
I had to install the ones for the Indy heads. The exchange was a success, but the noise remains. I can hear the sound when driving the car, but not at idle. It is engine related, not drivetrain, because it changes with rpm. The funny thing is that I can not hear anything at all when idling -- even using a engine stethoscope. All I hear is a rotational whirring sound. I guess I will drive it until something breaks and then I will know what it was.....