as far as I know that our 5EAT cooling spec is withen a special cooler that is a factory fitted to our engines. the cooler is between the engine and the engine oil filter. It is also used to cool the engine oil.
I've already installed an oil cooler for the engine and it is really good with our weather so far but too expensive. I used a Greddy Oil Cooler Adapter plate that came with a thermostate and a B&M oil cooler with a fan and a thermostate switch for the fan.
About LGT koyo performance radiator in our H6, what we need to do is to remove the marked area in the attached photo and get a new plate with two outlets insted of one outlet. There is also a small coolant return that we could use with a water cooled intercooler. All the other things like the fan mounts and the harness holder that runs beneath the radiator all the same and I already checked that.
If you need any other info, please ask