Much more normally a hybrid conversion with an RB30E block and also a twin cam RB25 head without a turbo can be used being a foundation for the RB30DE.The RB25DE cylinder head from the A31 Cefiro C33 Laurel or R32 Skyline (aka: Non VCT) might be used. The RB25DET (within the R33 Skyline or C34 Laurel or Stagea) head is likewise used, nevertheless a