Some came with limited manufacturing head P8R which had 33mm intake valves (Usually discovered on VTEC B-series) vs 31mm ingestion (non VTEC B series), and The top had an 84mm shrouding vs 81mm for all other B series heads. Identification: (ninety eight spec) PR3 stamp on engine head, major radiator https://b16-engine-and-transmissi02345.canariblogs.com/the-b16-engine-for-sale-diaries-54635714