Tom, the block casting number suggests a 54-55 block. Those blocks don't always have captains bars. Theses early 261 blocks can be bored larger then the later 261 blocks. Not a full flow, so can you confirm the smaller port for the smaller lines, like 235 size? The head is the common 86.2 cc 54-63 261 head. Has a 58-63 valve cover with the four attachment screws and center breather. But does not have the front 55-58 style motor mounts. Does not look like it has the later side mount bosses but I can’t really tell looking at the pass side of the block but maybe on the drivers side. If they are, they don’t look drilled but could be just filled with crud. Am I missing it or are there two bosses on the drivers side for a generator bracket? Early style style pre 55 water pump. So without taking it apart and looking for the steam vents and measuring the bore, looks outwardly like a 54 model year 261 but some of it is a mystery. Any chance it has the motor mount under the timing cover? Where did you find the casting date?

Wait, I see it. That is perplexing.
Mike

Last edited by mdonohue05; 11/09/18 06:38 PM.