Lost my Fuel and Temp Guages at the dash in my 67 Dart

If moving the fuse box causes the the problem to come and go I would suspect the pin on the back of the cir board on the gauge cluster.

The path goes as the following.

FROM the ignition switch a black wire goes to a splice.

From the splice it goes to a pink wire to the wiper switch and to 3 black wires. One TO the signal flasher, one TO the fuse block where it turns to red with a tracer and goes TO the radio, the third goes TO the instrument panel to feed 12v to the IVR.

So the power for all these things does not come from the fuse block it comes from the ignition switch and the feed TO the ignition switch comes from the main splice from the alternator.

There are no fuses in this path (except TO the radio)

So wiggling the fuse block is most likely wiggling wires under the dash causing the open connection to the gauge cluster.

You can check if the radio, turn signals, or wipers work or cut out when wiggling the fuse block