carter AFB troubles

Sounds like you might need to change your step-up piston springs at the metering rods. A surge can indicate either a rich or lean condition, so the overall performance would dictate which way to go on springs, heavier or lighter. I think lighter causes greater sensitivity to vacuum, hence slightly richer mixture at part throttle cruise, but not absolutely sure. You can get a kit with assortment of spring weights and go from there. Nope, don't have part number, except for Edelbrock asst. kit.