A filter inside of the carb was an option on Zenith carbs. AC made a porous filter for the fuel pumps that we called stone filters. I use them on the ones I have and put an inline filter between the carb and fuel pump on the ones that don't have one at the pump. I don't have much trouble with trash because when I get another jalopy, the first thing I do is put a new Spectra Premium tank in it.
