Some arrived with constrained production head P8R which had 33mm intake valves (Generally found on VTEC B-series) vs 31mm ingestion (non VTEC B series), and the head had an 84mm shrouding vs 81mm for all other B series heads. The B16B is like a shorter stroke equivalent in the B18 https://b16b-motor24568.atualblog.com/46409794/the-smart-trick-of-b16-crate-engine-that-nobody-is-discussing