text: The Nismo RB26DETT N1 engine block uses an  bore which can be bored up to either . The N1 block is cast with an identification mark of 24U, whereas the standard RB26DETT block is marked with 05U. The RB26DETT N1 block is compatible with all GT-R engine bays.
  RB26DETT Z1 and Z2
  The RB26DETT Z1 and Z2 (and often referred to as an "RB28DETT Z1/Z2") was the engine used in the Nissan Skyline GT-R Z-Tune built by Nismo. It uses a stronger RB26 block based on Nissan's Le Mans GT2 and GT500 racing vehicles (stamped with RRR), stroked crankshaft, upgraded turbochargers, and a higher bore and stroke at a displacement of 2.8 L. It produces  and  of torque. The 'Z2' revision includes upgraded turbochargers supplied by IHI, and additional improvements to allow it to reach maximum RPM speeds of up to 8,000 rpm.
  RB30 (3.0L I6)
  RB30E/ET
  RB30 were produced from 1985 - 1991:
  RB30S GQ Patrol - carburetted single-cam  at 4,800 rpm,  at 3000 rpm
  Powertech 6Ei (RB30E) VL Commodore - fuel-injected single-cam  at 5,200 rpm,  at 3,600 rpm)
  RB30E R31 Skyline - fuel-injected single-cam  at 5,200 rpm,  at 3,600 rpm) Initially quoted as 117 kW, 252 N⋅m but later revised
  RB30E R31 Skyline GTS1 - fuel-injected single-cam  at 5,500 rpm,  at 3,900 rpm)
  RB30E R31 Skyline GTS2 - fuel-injected single-cam  at 5,600 rpm,  at 4,400 rpm)
  Powertech 6EiT (RB30ET) VL Commodore - fuel-injected single-cam turbo  at 5,600 rpm,  at 3,200 rpm)