You can buy a kit as cheap as 20 bucks that has the refrigerant and oil as well as the adaptors. I wouldnt use it though. If I was gonna convert, which I would not, I would have a reputable shop do it the right way and just pay the good money to do so. It would be worth the extra cash.

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1984 300SD Orient Red/ Palomino
1989 560SEC
2016 Mazda 6 6 speed manual
1995 Ford F-150 reg cab 4.9 5speed manual