Circling back to this. Disconnected the speedo cable and drove the car. Same "fluttering" noise as before. Definitely speed sensitive in terms of the frequency of the flutter. Thinking a bad speedo cable may still give the noise even when disconnected from the head. If that is true or possible, can I disconnect the speedo cable at the trans and drive the car ( secure it of course)? a833 trans if that makes a difference.
I do not believe this could be release bearing related. Not loud or grinding - just very similar to a speedo that would commonly jump around at speed. Thanks all