1950s '56 Air Conditioning compressor

[Robertsup3]

Can someone please let me know if a '57 Cadillac air conditioning compressor fit on a '56 Cadillac, and if so, is it an exact fit/exchange?  In those years, it seems so many components were one-year only.  Additionally, internally, are they the same?

Thanks very much. 

[J. Gomez]

Can someone please let me know if a '57 Cadillac air conditioning compressor fit on a '56 Cadillac, and if so, is it an exact fit/exchange?  In those years, it seems so many components were one-year only.  Additionally, internally, are they the same?

Thanks very much. 

There is a post regarding the same topic/question as yours, here is the link;

https://forums.cadillaclasalle.club/index.php?topic=175651.msg562356#msg562356