Really responsible persons along with the engine is working perfect after a few months of use. Remarkably advised.The RB25DE cylinder head in the A31 Cefiro C33 Laurel or R32 Skyline (aka: Non VCT) could be used. The RB25DET (with the R33 Skyline or C34 Laurel or Stagea) head is usually used, however an external oil feed needs to be fabricated with