12000-ZZ5-415ZA Block Assembly *NH8* - Overview. The 12000-ZZ5-415ZA Block Assembly *NH8* is an essential component of Honda marine engine systems. This integral cylinder block assembly supports the engine's core functionality by housing the cylinders where combustion occurs. Designed specifically for compatibility with Honda marine engines identified by the *NH8* code, it ensures seamless integration with existing parts, maintaining optimal performance and durability.. Key Features. Genuine OEM