Some came with minimal production head P8R which had 33mm consumption valves (Ordinarily uncovered on VTEC B-series) vs 31mm intake (non VTEC B series), and The top had an 84mm shrouding vs 81mm for all other B series heads. The B16B is like a shorter stroke equivalent in the B18 https://b16crateengine90123.mpeblog.com/71213097/the-definitive-guide-to-b16-crate-engine