Based on info read here and elsewhere, I'm 90% sure its the governor gear.

1. I have headers, does the drivers side have to come off completely, or just loosened? Do I need a new gasket to reinstall?

1a. My dipstick tube extension goes through the header, does it have to come off?

2. Can I do it all from the cockpit, or do I pull the fender well cover?

3. I have fender flares, do I need to remove the flare to remove the fender well cover?

4. Should I also replace the speedo cable, in case it was the culprit?

5. My tranny is a Danny Dunn rebuild from the 90's, if that matters.

6. I do not know the origin of the headers. (probably installed by Ken Frey)

7. My records from the PO show the governor gear replaced in 2009.

We are not stranded on the side of the road. We limped it back to storage, very slowly. This is not urgent, I can't work on it again until Saturday. I just need an efficient plan of attack.