I recently acquired a '49 Mercury which seems to have an EAB engine or, the EAB heads on the original '49 Mercury block. ... Is this a possibility? Or is it more likely that the entire engine is a '52 or later replacement?
Welcome to the HAMB from Illinois. I suggest you post your flathead question over here, to get more views: https://www.jalopyjournal.com/forum/forums/the-hokey-ass-message-board.5/