So you have a 6 bolt 260Z pressure plate (240mm plate) with a 225 mm friction disc and it all fits?
When I modified my engine I was told that I should use a 240mm clutch but that it would fit my 240Z flywheel. However the 240Z flywhel is machined for a 225mm disc and has a groove running around it within the 240mm diameter. That groove would impact on the working of the friction disc.
What you have seems to be a mixture of the 2 clutches and I'm not sure why you would use that. Also the 240mm pressure plate is heavier than a 225mm one.
I would stick with one or the other, not a mixture. Why are you asking anyway Moggy, what are you trying to do?