12000-ZY6-445ZA Block Assembly *NH8* - Overview. The 12000-ZY6-445ZA Block Assembly *NH8* is a critical component of Honda marine engine systems. This OEM engine block, finished in the distinctive DARK GRAY *NH8* color, supports the core structure of the engine, ensuring mechanical integrity and durability. Designed to interface seamlessly with the marine engine system, it plays a key role in maintaining the reliable operation and performance of Honda marine power units. Engineered to factory sp