Originally Posted by 1971BB427

"These Holley Trick Kits are the inexpensive solution to fuel slosh in your carburetor. The kits contain all of the parts you need to perform a complete rebuild on your Holley carb, including a vent baffle, high-flow needle and seat assemblies, high-capacity power valves, pump cam and secondary opening spring assortments, gaskets, and O-rings. Plus, they have extra parts related to carburetor calibration that are required in order to accomplish a real performance tune. These include accelerator pump discharge nozzles and extra gaskets. A carburetor exploded view and detailed tuning guide are also included, with packaging that serves as a handy parts tray. These Holley Trick Kits have it all."

I'd consider pulling a swab through the gas lines. I usually use a vacuum to suck a strong twine through the gas line, then tie a small piece of cloth that fits inside the fuel line to the end and pull the swab through to clean all the crud out of the line. You could change filters for a long time, and never get it all out without either cleaning or replacing that fuel line.