I was looking at installing new Brembo cross drilled & slotted brake rotors with high performance (semi-metallic or ceramic) pads on my '90 Z32 2+2 N/A. I noticed that most of the rotors advertised are for 7/'90 to '96 (30mm calibers). Obviously, I do not have the 30mm calibers. Can someone tell me what they actually are? Should I upgrade to 30mm calibers? If so, is it a 'bolt on' replacement, or do I have to buy a kit to offset the calibers appropriately?
Thanks!

 

us early 90 models only have 28 mm calipers

some ebayers actually sell 28 mm rotors as well, so you can do that too if you want

30 mm calipers will fit with no modification