i have a upgraded clutch cylinder in my gtr and my clutch is heavy as!!!
i have a twin plate clutch which is probly the reason for it being so heavy, and when your not moving and i put the clutch in i can hear a metal on metal rubbing noise, and it also squeels if you try ride it, it's on or off.
my mechanic indicates that if you can't hear a rubbing noise when you put the clutch in, it's a single plate clutch cause they buff out the noise where as a twin plate doesn't.
they should both squeel when they are being ridden, this is a indicator to stop riding it or your doing a big launch which is putting some pressure on it.