Extra frequently a hybrid conversion having an RB30E block plus a twin cam RB25 head without having a turbo is also used to be a foundation for the RB30DE. The RB25DE cylinder head from the A31 Cefiro C33 Laurel or R32 Skyline (aka: Non VCT) may be used. The RB25DET (with the R33 Skyline or C34 L