Speeometer/odometer

I replaced the gauge cluster in my 67 Dart GT. It included a new speedometer cable. Everything is working beautifully (gauges etc) except the speedometer and odometer. The needle will occaisionally move to an area and stick there for a time. I have unfastened and reconnected at both ends of the cable housing with no result.
Any ideas/suggestions?

Whenever I mess with a speedo cable on these cars I take it as a given that I will have to jack up the back wheels, run the car in gear and mess with the cable angle into the speedo head until I get it where they run smooth.