AC Compressor parts #'s

[viclava]

I have a 92 Legacy LS with a CAlsonic compressor. Part # 73011 AA090 with a 4 prong electricla connector. I got a hold of a 91 compressor (Calsonic) part # 73011 AA031. I thought I remember my local Subraru parts dealer telling me it should work, but when I saw the electrical connector and the last 3 part #'s being different, I'm not sure.

 

Can anyone shed some light on this for me. Thabks in advance.

Scott