On the side of the top flange that bolts to the manifold, there should be a date code, opposite of the 389/95.For example, my VMCC certificate for my 1967 T120R has despatch date of November 23 1966 and the carbs are stamped 11/66 on the flange. The date stamp is generally on the topside flange but I have seen them on the underside and carbs without them, also.