This is the "lung" if the engine, and it's the least of our souping worries. Stock carbs are right at home feeding red-hot setups, and in fact, there's very little we can do to increase their efficiency. Ford carbs are no exception in this respect, being used almost exclusively on souped Ford-Merc V8s. Except for the first 1932 and '33 models, all Fords prior to '37 used the duplex Stromberg EE-1 Model "48" carb, with 1.03-in. venturi and 0.048-in. main jets. In 1937 the Stromberg Model "97" was adopted, with the same layout, but using 0.97-in. venturis and 0.045 jets. (Fig 7-2 shows the layout of these carbs). In 1938, Ford began sponsoring the production of their own carbs through Chandler-Groves (Holley) and succeeding models were known as "91-99" and "59A" for the post-war engine; these carbs are similar to the old Strombergs, but there is a removable nozzle bar and the main jets are "buried" in the fuel bowl. Venturi diameter here is 0.94 in. and 0.050-in. main jets are standard. For 1949 and later engines, Mercury went to a right-angle Holley carb; these are not too suitable for souping work, so we won't discuss them further. Now our problem in carbureting a souped V8 is merely one of selecting venturi and jet sizes that will give us the desired mixture ratio and air flow under the various conditions with dual carbs, hot cams, porting, larger displacements, etc. However, since the carb is designed to meter fuel according to the flow rate through the barrel, adding carbs, cams, displacement, etc. doesn;t upset this balance, and the carb just meters more or less fuel as the air flow thrugh the barrel is increased or decreased. So you can just as well run standard jets and venturis as not.