OEM NUMBER LOCATION BY MANUFACTURER HOW MANY BARRELS? If you are not sure how many barrels your carburetor has or how to locate the OEM Number? Use our guide to figure it out. 1 Barrel Base 2 Barrel Base 4 Barrel Base 1 Barrel Carter 1 Barrel Ford 1 Barrel Holley 1 Barrel Marvel 1 Barrel Rochester 1 Barrel Stromberg 2 Barrel Carter 2 Barrel Ford 2 Barrel Holley 2 Barrel Rochester 2 Barrel Stromberg 4 Barrel Carter 4 Barrel Ford 4 Barrel Holley 4 Barrel Rochester