S30 Spring Specs
There are many spring options available for the 1970 - 1978 S30 Z cars. In addition to the normal after market springs available (Eibach, Tokico, ect) you can also use springs from other S30s. All S30 springs interchange with no fitment issues.
While the S30 springs will fit in any S30, there will be a slight shift in ride height depending on what model you have and what springs you end up using.