On Ford Holley 6V carburetors you will have an official Ford Part number and the Holley List number. SBF List 2667/2668 260 (730CFM), List 2881/2882 289 (675CFM), List 2436/2437 FE (1030CFM), List 2497/2498/2499 FE (1030CFM) and List 3208/3208/3208 FE (860CFM)