I have a 1990 240sx and im installing a type x black top SR20 and I hear that I must change my cluster to a 1991 and up in order for it to function with the SR otherwise the RPM’s will not work. Is this true?
I thinks so. AFAIK, the SOHC tach signal and DOHC tach signals are different.
Don’t change the cluster, just get a tach portion from a dohc and replace the sohc tach in your existing cluster.
Stuff need to change but Mikes suggestion is the best way