If you have a working R12 AC system, and your 7M swap includes a working 7M AC compressor, all you'd need to find is a shopI'm curious. If I do a 7m swap into my 84. Even though I have a working ac system now, what would the cost be to have the system evacuated and refilled with custom lines to the 7m compressor? Will I need to get this retrofit kit? Will r12 work with the 7m compressor?