Originally Posted by 10 GT3

This is very unnecessary unless you are upgrading to much larger brakes. Stock master cylinder is more than adequate. Good brake flush with good racing fluid (Motul 600 for example) results in really good pedal feel. Beyond that, nothing gives a firmer feel than installing stainless steel brake lines. GT3 has different master cylinder with proportioning due to the much larger fluid flow needed for the larger brake calipers. Due to the significantly larger front calipers, it has more front brake bias. Just installing this on a 986/987 could very easily cause a brake balance shift that the driver may not be ready for. I assume in posting this add that you are willing to accept that liability.