This just in, the compressors are the same, save for one small problem. The condensor and compressor hoses that link up at the back of the compressor are different. They are held by a flange that has one bolt that holds them to the compressor. On the 93, the hoses ends are even. On the 94, one is a little longer. So that when you put a 94 compressor on a 93, one hose is a little to short to seal properly. There is a little kit available from O"reilly and probably others, but not Autozone or Advance, that includes a little washer to fill the gap to create a good seal.
I assume this difference is because a 93 comes with R12 and a 94 came with R134a, and to create awareness that you should have a system with the proper freon.