Rust, dirt in gas tank?

you place a large 40-100 micron filter before the pump (gerotor or EFI style) and then the fine <34 one before the carb/injectors. Now the Bosch Jetronic fuel filters were uber fine (5 microns!) as the pinholes in those distribution valves were microscopic. BTW, you already run 2 filters...the sock being 1 and the inline being #2 but the sock is most likely gone now. The one I took out was just rust, and when I blew compressed air in from the line side, it just went up in a cloud of dust.