Are you sure the calipers are the 30mm version? I have 30mm calipers and rotors on my car and the clearance is nowhere near that tight. *Referring to the last picture.
This is the brake swap guide I used and it shows the difference between the three 300zx calipers.
http://importnut.net/300zxbrakeswap.htm
Sent from my VS980 4G using Tapatalk