Genuine Reliabilt remanufactured Detroit Diesel high-flow oil pump, part number R23530487. Fits Series 50 8.5L engines. NOS (new old stock) condition in original packaging. No core charge or return required. Price is firm as listed unless “offers” enabled. Unsolicited discount requests will be ignored; repeated messaging may result in blocking. Honest mistake or fitment question? Message me first, happy to work it out!