Maybe r32 and r33, gtr and gtst and z32 calipers are different in this regard. To fit them to a set of 330mm discs, we had to grind the inside edge of the caliper almost all the way to the bolt that holds the caliper together, which i consider far from optimal. This allowed the edge of the pad to be almost flush with the edge of the disc with the inside of the caliper being about 1.5mm from the disc. However maybe the calipers were different, or the pads, or even the discs possibly. We did question this at the time as i knew UAS sold brackets, and we couldnt see how this was done commercially. PS Im not sure which calipers we had(They all look the same, but i was told they were 33gtst)