Instrument Voltage Regulator

Don't you need to modify the fuel gauge to eliminate the original voltage limiter circuit?

Yes, I had to modify the fuel gauge to disable the old voltage limiter.

If ya have not re-installed that dash, yet, it'd be a good idea to replace the radio suppression capacitor (condenser) If it shorts, bad things

Should be available from any "real" parts store, ask for a "radio suppression capacitor" or look through the pictorial guide for just about anything with similar mount. You might have to cut and splice the wire

Is this a common problem? I have not heard of the issue. I can easily reach up there and disconnect it.