Any AC compressor conversions for R134A?

[Thunderace1997]

I have a 91 Suburban with the 350 in it. The compressor for the AC has stopped working. The AC was converted to R134A a year or two ago by the previous owner. The truck only has 52k original miles on it. I was told by a shop that the R134A will lower the life on compressors that were designed for R12. Is that true?

If that is true will the remans be set up for R134A or R12? If the remans are set up for R12 is there one set up for R134A that I can swap from another vehicle?

Thanks.