Thanks for the replies I have both liquid filled gauges on my car and both are located under the hood. The fuel filter is mounted just above the gas tank just before the fuel pump which is also located just above the gas tank. and the pressure at startup when cold is about 7-9 PSI then drops when the car is warm. never thought about liquid pressure buildup in the gauges. I called Edelbrock about that and they said it should not matter about liquid filled or dry type gauges and they Edelbrock stated that my type of carburetor with vacuum secondary should not have more than 5.5 PSI going to it at operating temperatures. But Firebob mine does what you stated in the forum listed above. I also get 13.5 volts now at the fuel pump relay and at the fuel pump. I also removed the SUMMIT Racing -8 100 micron fuel filter summit part number SUM-230118R it had some minor trash in it but did not put it back on the vehicle . and the fuel pressure is exactly what Firebob described it about 7-9 PSI at cold start and now its at 4 psi when at normal temperature. im going to try to reinstall the fuel filter Sunday and see if I get the same results and previously listed [7-9] PSI at startup the [3-4] PSI at operating temperatures.
In closing why have liquid filled gauges if they are prone to this types of problems I guess live and learn next time I am getting dry gauges. whats the advantage of liquid filled gauges compared to dry gauges. .