So I had 2 AC compressors. My original and one someone gave me a long time ago. My car has been totally apart for a very long time. It’s a frame off and now things are really coming together. I rebuilt the wrong compressor by mistake. The original AC compressor was a model: 5910738. The compressor that we installed the new seals and o-rings on was a model 1131443. The 443 was used from 77 to 80 in Buicks. When the rebuilt 443 unit didn’t fit, I seen why. The front mounting bracket had an offset to it. The 443 unit also had a pressure switch on the back, which my original did not. The 738 was used in the 60s to the early 80s on a whole lot of GM cars. The a6 compressors look so similar. Also the pulley seems different. Am I screwed and I have to do the same rebuild to my 738? I know that I could swap the mounting plates. The extra pressure switch won’t be hooked up and it seems like the pulley position for proper belt alignment might be off. Should I try to switch pulleys and mounting plates?

 

Here are the two compressors.