My reference material shows the heads to be 57-61 283 truck. The date codes E167/E237 E=month/day/year = May 16/23 1957. I can't help you with the other numbers but if it has a 4 bl manifold it would not be factory. There are lots of stories out there but I doubt that he ordered "factory high performance options" on a truck. Not to say that a dealer wouldn't install them per a customer's requirement, for a price.
Fred
