Jep...try using search facility, type in oil cooler. This topic has been discuss before. But frankly, I never seen any topic discussing oil cooler for seg before. Hopefully there are sifus can assist you. Good luck dude.
Nissan never actually produced an RB30 with the Double Over Head Cam (DOHC) cylinder head for SKYLINE SILVIA or FAIRLADY. The RB30 block was produced by Nissan for the Holden company...