In general, the latter year flatheads were commonly referred to as the "8BA" type for Ford and "8CM" for Mercury. The truck version was identified as an "8RT". Later 1952 and '53 Fords and Mercurys were known as "EAB" and "EAC" respectively. These markings are generally cast into the cylinder heads. Be aware that all these heads are interchangeable and may not be on the original engines.