Also, improve the protection capabilities like the brakes and seat belts. Some even insert a roll cage for cover in the event of a collision.The RB25DE cylinder head with the A31 Cefiro C33 Laurel or R32 Skyline (aka: Non VCT) is often used. The RB25DET (from your R33 Skyline or C34 Laurel or Stagea) head can be used, having said that an exterior o