41 1 1/2 ton dump truck. 216 w/rochester.While revving engine there is a stumble or cough before getting up to rpm.Carb seams to be in order,viewed all Mikes Carburator vids every thing checks out. Maybe I dont know how to tune it correctly. Points look good, coil tested ok,Vacum advance functions with vacum test,although sort of sticky,plugs look good. Certainly confused.Any help would be appreciated. Thanks