Thanks for that info funola, I also just spoke with a rep from RedTek and they said they are almost sure our cars dont use the incompatible butyl hoses. They said those are cheap hoses normally found on buses. R12 orings are also compatible with r12a so there is no need to change them unless you want to be proactive (not a bad idea on an old system). I managed to score some cans of real r12 so I am going to charge the system with that instead, but at this point I think 12a would be feasible for our cars and I would use it if i didnt have r12, you will just need to diy because I dont think a shop will hook up their equipment to 12a. And I wont be using the crappy delco r4, instead I have installed the klima sanden conversion kit. The install was pretty straight forward for a conversion and the parts were good quality.