The D in the engine code means twin overhead camshaft (DOHC). This is certainly attained by fitting an RB25DE or RB26DETT cylinder head and or turbo to a typical RB30E/T block. The RB25DET just isn't typically used.The RB25 crank collar situation is really quite common on several RB motors, such as the RB20DET and pre-1993 RB26DETT. The condition W