Instrument Cluster Voltage Regulator

Fuel gauges with 3 contact/mounting posts have the voltage liniter built inside. All other typical gauges have only 2 posts. Early a-body panels and the rallye panel found in 67 through 71 second generation A-body have 3 post gauges.
RedFish this is Boris and i have a 1964 barracuda and i have been trying to find the voltage limiter and did not realize it may be in the fuel Gage. Do you have one for sale. My fuel gage and temp gage do not work and i replaced the circuit board already. Please help