Some arrived with constrained manufacturing head P8R which had 33mm intake valves (Usually identified on VTEC B-series) vs 31mm ingestion (non VTEC B series), and the head experienced an 84mm shrouding vs 81mm for all other B series heads. Even crazier is this engine continue to has substantial tuning opportunity, https://elliotiogvh.idblogmaker.com/38645741/not-known-details-about-jdm-honda-engine