Skyline A/c Questions

[GSX-R35]

I had a couple of questions I was hoping someone knowledgeable about Skyline AC systems could answer. I wasn't sure what section was best to post this thread so apologies to the mods if it should be somewhere elas.

1. Will an R33 A/C compressor fit without modification to a different RB26 engine, say one meant for an R34? The reason I ask is because I'm planning on swapping the old tired motor in my R32 for a newer one meant for an R34 and since my car is a 1990 with the old R12 refrigerant that you can't get now I figured now would be a good time to swap the compressor for a newer one meant to run R134a and convert the system over.

2. Did all R33s use R134a? I know late model R32s were supposed to have switched so I assume the R33s had R134 systems but I just wanted to be sure. I've seen some used R33 compressors online and figured it'd be a safer bet to get one of those than get the wrong type of R32 compressor by mistake.

Thanks in advance for your replies.