I have an R12 compressor that works, and then another one thats R134A. It looks like the only difference is the ports on it. The R134A compressor is the one I need and its locked however the R12 compressor is not.

My question is, does anyone know if the internals on them are the same thing? I would like to save myself some money and remove the internals from one, and throw them in another. Although I don't want to waste my time if its impossible. Might anyone have an answer for me?