This is the correct 215mm aluminum Pressure Plate https://pbase.com/9146gt/image/33571771 used on the 2.0 liter Carrera 6 engines. The pressure plate is "NLA" (No Longer Available from your local Porsche dealer) and are very difficult to find. If you're lucky, you might come across these parts on eBay for about 850 Euros.

The 215mm aluminum pressure plate was rated for the 2.0 liter engines with up to 235 h.p. (approx.). These were later improved with a larger 225mm pressure plates, those are not necessarily vintage correct for a 914-6 GT, but work much better in higher horsepower applications.