The D within the engine code means twin overhead camshaft (DOHC). That is accomplished by fitting an RB25DE or RB26DETT cylinder head and or turbo to a regular RB30E/T block. The RB25DET is not commonly used. When originally supposed with the R32 GT-R and Group A touring motor vehicle racing, https://andreoomjg.buyoutblog.com/28295332/rb26-engine-for-sale-an-overview