The speedo in my '65 did the same thing. Noisy as can be in cold weather and once in a while the screeching and needle pegging thing. I had it rebuilt thinking that the head is the only place it could be. No change..... Thinking I had been taken for a ride by the speedo shop I had it redone again by another guy and I still have the problem, although not nearly as bad. I bought a brand new cable and housing unit and that didn't change a thing. When it starts its antics, I can reach underneath and play with the angle of the speedo cable and it stops. Loosen or tightening the cable housing nut doesn't have much effect. I'm thinking that I need to get under there and support the cable some how so that head isn't carrying all the stress of supporting the weight of the cable. Bailing wire come to mind. It's really not cold enough here in Tucson yet to give it a good test so I have to return and report.
