The important dimensions would be:
A. distance from the wheel center to the outside edge of the caliper
B. distance from the wheel center to the 'fattest' point on the caliper (the NISSAN script)
C. distance between the wheel mounting surface and the 'fattest' point on the caliper
as per this diagram:
If anyone with 300ZX brakes can fill those dimensions in, along with the type of caliper (26mm Al, 30mm Al, 30mm Fe), it would be much appreciated!