I have an '85 C10. Has anyone had any experience with the kits out to convert older vehicles to R-134a? Years ago, there seemed to be a big deal about such a conversion, but now the kits have, as the main component, a screw on fitting so that a R-134a connector can be used. Add oil, add refrigerant, and that's it. I bought such a kit, but before I commit myself, I thought I'd check this forum. The kit I have indicates that it should be filled with R-134a to 85% of the system's capacity, but it doesn't say why. Will my truck explode? Turn into a pumkin?n What? Any input will be appreciated.