Help identifying 331 heads

[CRAIG LEWIS]

I need help with identifying these heads. I saw a post on the 331 EUN #'s and verified I have a 4S45907 stamped on the engine bell housing. According to the post this is a 1953 EUN. However the post showed head numbers 3630323 right, 3630324 left. This seems wrong as I have no such numbers cast or stamped on my heads. I have:
1459736-7 with a 4 below for left and 1459736-7 with a 3 above for right side. I also have numbers stamped on the center exhaust port flange but i think these were not factory stampings. not sure what they are: P 26642 with a 1 stamped over the 2 on the left side and 51655 with an upside down 2 over the last 5.  I suspect at some point the heads were redone and they were stamped 1 and 2 to ID right and left. Not sure what the other numbers were for. I also  do not have the Cadillac VIN number on the block right cylinder deck KA56457near the water pump where they are typically found. It is stamped but with the following VIN KA56457CA either I or L.

Anyone have any ideas what I have my hands on?

Thanks
Craig

[Philippe M. Ruel]

The trouble with books is that they often give part numbers, that are often different from casting numbers.

The casting numbers you have are of a 1953 331.