Speedometer faster than actaul speed plz read details.?
I own a 67 also. Does the speedometer read 30mph when you are stopped? If so, get your speedometer rebuilt, or replace it with one from an aftermarket company.
If the problem is exponential (the gap between actual speed and displayed speed gets greater the faster you go) then the problem is the speedo gear in the trans. If you remove the single bolt that holds the speedo cable in the trans, and pull the cable out, there is a small plastic gear on the end of the cable that is held to the cable by a small C-clip. This will have to be replaced with the appropriate gear. Most mechanics have a chart that has which gear is right for which rear axle gears and which size tires, as well as the transmission the car has.
Good luck with your speedometer woes!