My Temp Gauge and Fuel Gauge aren't working...
Have you guys tried the "build your own voltage limiter" fix?
http://www.allpar.com/history/mopar/electrical2.html
My ammetere was the only gauge working in my '67. The dash lights and blinker indicators didn't even work. A "new" voltage limiter was going to be almost $40! I paid less than 10 at my local Radio Shack, made my own limiter / regulator, mounted it in the stock position, and VIOLA! All my gauges work better than ever, my lights shine on, and I can tell which one of my blinkers is flashing again.
I even clipped the prongs off of my old voltage limiter and soldered the wires onto them, so that they could plug into the stock position and I wasn't soldering directly onto my vintage dash.
This is easily the best mod I've done. Cheap and easy, yielding superb results.