How much horsepower does an edelbrock carb add?

Edelbrock carburetors do not necessarily "add" horsepower to an engine. While they may improve certain performance characteristics, such as throttle response or fuel efficiency, the actual power output depends on a variety of factors, including engine size, camshaft profile, intake manifold, exhaust system, and overall engine tune. The specific gain in horsepower would also vary based on the specific Edelbrock carburetor model and the particular vehicle or application it is used in.