1968 barracuda temp gauge and fuel level inop

Oil gauge operates on same regulator as temp and fuel. If oil gauge works regulator is not the problem. Must be 837642 threads here about these gauges. Read them all. Pay attention to the percentage of do it yourselfers who do it over and over again.
Even if a solid state regulator does get needle movement from these 40 to 50 year old gauges, they aint gonna be accurate.