Milly compressor difference by year?
 

The compressor failed on my 2000 milly S. I am looking to get a used one to replace it with so I can sell the car. My question is, which year did the compressor change in? I believe I read that there is a difference and that the older style will not work as a replacement for me. What years will work as a replacement for my 2000?

Thanks,

Eric