Vehicle A/C Compressor type?

Im planning on converting my cars A/C system over to r-134A and wanted to know why type of PAG oil i would need for it. I was told that PAG 150 was used in my vehicle, however some models used different compressors and different compressors need different oil.... I have a 1992 Olds cutl ciera SL with a 3.3l engine, does anyone know what type of compressor is in my vehicle, and/or what type of PAG oil i need?