Edelbrock part throttle surge help

many years ago a friend had a 1968 dodge van with a slant 6. it had a lean idle. holley carb 1 bbl. getting to the idle jet on it was very hard compared to a carter. the short story is it ran so good it would idle at 250 RPM very smooth. coarse that was not RPM we used on the street it at. but it didnt die at stop lights and black smoke didnt roll when you started it up. i said it really put out WAY less pollution after.