[Richard]

I am retrofitting factory A/C converted to R134a. The cycling clutch system used in later systems and aftermarket was designed as a cost cutting measure. Obviously it works as it is installed in millions of vehicles, but not necessarily better. Aftermarket systems are designed to be compact, air passages are cramped and restricted. Less BTU's. Servicing is not easy. Fresh air is eliminated with all of them as well. If you have all the original A/C parts no reason not to use unless you prefer a cleaner firewall and the disadvantages I mentioned.