I’m in the process of buying a boat with a 312 interceptor with dual side draft Carter carbs. The past owner had trouble with the carbs and couldn't get them to run correctly. I would like to rebuild the carbs or replace the intake with a 4 bbl intake with a modern marine carb. It seems that the stock intake with the side draft carbs can be a fire hazard and are difficult to adjust. If I were to buy an ECZ 9425 B intake what size or brand of carburetor should I buy? I would like to buy a new marine Holley or Edelbrock with an electronic choke. How many CFMs would be adequate for a stock marine 312? Is 600 too much? Holly sells a 450 cfm marine 4 bbl. What modifications would I have to do to get the intake to fit and run? I do understand I might have to add height to the engine box. Thanks for your time.