I have a 1992 5.0 5 speed LX Coupe this past 2 weeks I replaced the Heater Core so I had the dash all out and I also replaced the gauge faces in the factory cluster. Now before for I had it all apart my speedometer needle was a little jumpy at slow speeds, but now its seem to be even worse. I see on Latemodel Restoration there seems to be two likely causes my Voltage Regulator for the Instrument Cluster, or the speedometer cable. The regulator they say can cause jumpy needles but only my speedometer is acting up, on the other hand they say if the speedometer cable is gone or not properly lubricated it can cause the needle to jump also. Here's my thinking now it's likely the speedometer cable but they have 2 one for a car with a speed sensor and one for a car with out one, how do I know witch one I need?