I've removed the speedo cable and the ends look fine. I lubed the cable and there is no difference. In fact, at times the speedo will show 10-20 mph when the car is not moving. I guess I need to tear apart the whole darn dash to get the speedo out so I can take a look. I'm guessing some kind of return spring or the magnets...
That is the last thing to do!
Replace speedo cable first .
A speedometer can read as high as your saying if the transmission has let's say a gear for a passenger car like a 318 Satellite with a 2.45 rearend ratio and you actually have 4.10-5.38's. Seen it been there. Mark the tire and mark the driveshaft and get an idea of what gear set is installed by counting the # of turns the driveshaft spins to one turn of the tire.
Then pull the speedo gear from trans and put in correct one.
If all that checks out maybe you have a bad speedo head.
