Well, old school wise, I'd go 3310 750 (vaccum secondary) for a mild engine, mild gearing, or a 670 street Avenger VS. If you had to have a DP, I'd run a 4150 DP. Other choices are 625 Road Demon vaccum secondary, or 650 Speed Demon. The Avengers and Demons are flowed wet, so they are a true real world rating for airflow. The old Holleys are dry flowed, and truthfully flow about 10% less when on an engine and full of fuel. Demons are not Holleys, and can be a little finicky to get "right", but they are a better carburetor IMO.