As you may know I'm converting my 4x4 RS500 to air con, I have the bulkhead panel and blower/evaporator unit organised but am pondering on which direction I should go with regards the air con rad as I'm going to use a 500 sized intercooler.

I'm hoping to draw on personal experience and/or actual facts, anyone carried this out on a Sierra or Escos?

I have read some previous threads and noticed that the original cars used R12 refrigerant rather than the newer 134a and that the later gas requires a larger compressor (user foreignRS mentioned it) to produce the same performance as the earlier type. I don't mind adapting a later compressor, does anyone know any units that are better than others size for size? I have late compressors from Audi (VAG), Rover and Fords so would like to use one of those if possible.

Any info would be a help