I have a 1967 Chevy C20 pickup w/camper, 81m org miles 327 all org has set for set for several yrs. We cleaned out the fuel system & it runs but rough. It has a 4bbl carb, turning the idle screws seem to make no diffrence is there any other adjustment that cam be made? we’ve replaced the points & plugs
If turning the idle screw does nothing then you more than likely have a vacuum leak !