jsceach, thanks again for the reply/information. My dealer question, was more rhetorical, because Porsche used to sell OEM center radiator Y hoses that fit on the base car with no modification, and I am curious what they do when someone with one of the OEM kit's comes in for a repair and the Y hose sized for the base car is no longer available.
I have a 2.5L base and have been having an overheating issue, which I am fairly confident is either a bad thermostat or water pump. I am about to change the water pump, and install a low temp thermostat, and decided while I have the coolant drained from the car I would also like to install the center radiator to keep everything running as cool as possible.
I track the car a few days a year, but I am primarily interested in keeping the coolant (and in turn oil) as cool as possible to help keep my engine healthy over the long term.
Thanks again for the replies!