Thanks Chris - I was hoping I wasn't way off base.moparchris said:As far as the carbs being rated differently Carter to Holley is true. Carter flows their carbs at 5" of vacuum and Holley flows their 4 Barrels at 3". This makes a 630 Carter a 500 CFM Holley equivalent. Holley 2 barrels (six packs included) are flowed at 5" so they are really something like 930 CFM versus the advertised 1350 CFM.