I have a 1990 nissan 180sx, and I was wondering if 89-90 (4 bolt) 240sx brakes will fit on this? I have heard 180sx brakes are bigger than 240 brakes, but I always thought this was only on the 91+ models (5 bolt). So yea, will 240 brakes fit on my 180sx, or will I have to go to a jdm supplier/upgrade to Z brakes ?

 

91+ are not 5 bolt. I do know for sure that the 91+ 4 bolt silvia and 180sx brakes are slightly larger. I cannot say about the 89-90 ca18det models though. Easy way to tell is pull a rotor and take it down to an autoparts store to compare.