R-12 may be hard to come by or at least expensive. I have factory air and a full 30lbs container of R-12. It is definitely colder at idle with R-12. Since I have a numbers matching care and original AC it was a no brainer for me to keep it factory. You can buy the O-ring kit at a local place in Phoenix. Desert68 (a member here) picked them up for me and shipped them. I can get you the info if you want.

Ed

Here is the P/N CP3011 but I can't find where I bought them. Maybe Lambert (desert68) can remember? You may try a search on the net too.