Ok I know some will say just be a man and forget the a/c but kicking around idea of trying to get the old a/c working on the 79 Grand Prix we have. Just bought it in Sept and finally got it on the road. We now would like to be able to get the air condition working. Of course we have no idea as to how long it hasn’t worked since R12 is their anything short of completely changing the system that would work. Can I convert it to R134? If so what do I have to change to get it to work as it should? Kind of lost as to where to start. I really don’t want to change all of it if we don’t have to. Is there any options short of aftermarket a/c