Carb CFM recommendations

So you want me to buy every carb option and throw away the ones that do not work well? Really? 770 cfm is 30% more air than this engine can possibly consume.
Relax dude, trying to help. The way you wrote it is "the best options I have" I took to mean you already have the carbs. That's why I said "try them all". So if you haven't bought the carb, then I don't think you listed the best options you have. I have a 770 on my 318 because it outperformed the 600 eddy and 670 I had on it, ET proven. I have less of an engine than you. Good luck :)