I had a 72 Chevelle with guages at the time and the fuel and temp guages did not work. I was assembling an unfinished project and never experienced the printed circuit material before; bottom line was that some of the copper from the material was peeling back and was not making contact with the guage terminals. The copper was there, I just had to make sure it went over the guage terminals. You can get to the guages just by removing the dash pad. You probably already know that. Get yourself a good volt ohm meter and start testing the terminals on the guages to see if you have voltage and grounds. Make sure the ignition is on when testing for voltage. Also make sure you have good connections with your sending units.
Hope this helps.
Phil Woj.
Hope this helps.
Phil Woj.