Instrument Cluster

I have a 67 Dart as well and here's what I did for testing on the cluster as well as a solid state mod.
1) Get 12Vdc to the input of the regulator
2) Ground the regulator to the - side of the 12Vdc source
3) Test for 5VDC on the output of the regulator
4) Hold the input for the FUEL or TEMP gauges to ground, while the ground is being held the gauge will slowly move up, don't let the need peg out just verify it can go to maximum

It should all be the same with the non solid state regulator
Here's a pic https://www.dropbox.com/s/vzce78fb162ncf7/Instrument%20Cluster.jpg?dl=0