If we are to assume that your engine is otherwise stock, with a stock auto trans, and stock 2.75/3.00 gearing, you will do well to go 600 cfm, vacuum secondaries, automatic choke, standard 4160, with an automatic kick down for use with Ford's kick down arm. Because the 4 barrel carb will be centered slightly more forward on the manifold than the 2 barrel is, you should also buy Holley's 20-41 kickdown lever extension ( it's in all the Holley catalogs ), but rarely mentioned by do-it-yourselfers. Resist going to Brawlers, Ultras, Demons, Warriors, and such with OOOH-AHHHH titles, as you don't have a race car. Also, you don't need a double pumper. Your stock 2V engine will likely peak well before 5k, so big CFM carbs will not perform any better on your current combination. Google Holley's Catalog for part no.s and information and guidance straight from the manufacturer.
