Help Identifing Cadillac Head

Could anybody help me identify the year of the heads on my Cadillac 331 engine? The ID numbers on the left and right heads located under the valve covers read 1454022-3 on both. Thanks!

 

Anyone? Thanks

 

365 & 390 have much larger exhaust ports than 331. Don't know if that helps or not, just sayin'...

 

If anyone knows more I'd appreciate it, thanks

 

My interchange only goes back to 55 on Cadillac heads and the first three numbers are 146 so I would think pre 55.

 

I am looking for info also, my 331 is suppose to be a 1953 one of the head numbers is 1459736-1, also has IN22 on the head a short distance from the casting number that look strange (modern looking). Don' t know if this helps but ..............

 

Hi, that number is for 1951. I have an original 1951 Cadillac and the heads have that casting number.