Thickness of HKS Twin Plate clutch discs?

[lockwood77]

I\'m having my FD\'s gearbox swapped later this week and need the clutch checking whilst it\'s out. It\'s definitely a twin plate and from the amount of HKS gear on the car, I\'m guessing it\'s HKS.

I\'ve read in a couple of places (inc. RHD Japan here: http://www.rhdjapan.com/hks-gd-max-pro-clutch-parts-0215-replacement-disc-14201) that 4.2mm is the minimum you should run, with 4.6mm being the thickness when new.

Does that sound right to anyone? Could my clutch feasibly be a different model (assuming it is HKS at all) with a different disc thickness tolerance?