Pump pressure shouldn't go as high as 6 psi. 3 to 4 psi +/- 1/2 is the limit. You may be overcoming the inlet needle valve.
If you are running Ethanol, lower the float.
Rochester is known for leaking but Carter not so much.
Taking your carburetor to a professional (one who has the experience, the equipment and a selection of hard to find carburetor parts ) is a smart move IF you first make sure everything from the gas cap to the carburetor is in tip top shape.
If you must run Ethanol in a truck with original fuel system, don't let it sit 6 months unused. You must drain the fuel regardless off what additives you pour in the tank.
