Answer: There are many combinations of parts and kits available that can be used to complete the installation. The basic difference between the kits is what components are used in the engine compartment and what components are used in the passenger cabin.
In the engine compartment you can choose between an “original style” compressor, or a modern “Sanden style” compressor. Other engine compartment parts include the condenser, hoses, dryer, mounting brackets, and pulleys.
In the passenger cabin you can choose between a system that utilizes your existing heater and ventilation controls but requires the installation of under dash louvers to distribute cold air, or a system that includes its own controls and vents and hangs under the center of the dash. The latter is virtually identical to what would have been installed by the factory or the dealer in 1966, and therefore it looks aesthetically correct. It is for this reason, plus the ease of installation, that I prefer this unit for the passenger cabin portion of the system.
Which compressor and associated parts you choose to install under the hood should depend on how you use the car. I consider the modern “Sanden style” compressor along with its associated parts to be vastly superior to the “original style” compressor. It is smaller, lighter, more efficient, and virtually maintenance-free. However, when you open the hood, this piece of modern technology “sticks out like a sore thumb” against the backdrop of a 1960s engine compartment. If you show your car at events where adherence to originality is of paramount importance, you are stuck with the “original style” compressor.
If you consider yourself to be a fair “shade-tree” mechanic, you should have no problem installing any of these systems. Plan on a full day to do it right. Once the installation is complete I would suggest having it evacuated and charged by a qualified shop. They can check for any minor leaks and remedy them if necessary.