Carburetor size

After watching the video on sizing a carburetor, I was wondering if using the carb that I have (Holley 670 Street Avenger) would be too much carb for the engine. It's going on a 1971 340, rebuilt with. 030 over forged pistons and Edelbrock aluminum heads. Using the calculator, the carb should be around 487 cfm. This will be used as a street car. It's going in a 1970 Duster.
If I left out any pertinent information, I apologize.