Fuel filters will catch particulate matter to a degree, but not contaminants that are suspended in the solution. If the tank is not clean, you may have a repeat performance with the Holley carb as well. The Edelbrock carb can be taken apart & cleaned while you put a rebuild kit into it. If you have any thought that the tank is dirty, you should pull it and get it to a radiator shop to hot tank it. At the very least you should consider putting some fuel system cleaner into the tank for a few tanks to clean things out. Change your fuel filter a few times & use carb spray to clean the carb bores until the gunk is all cleaned out.