Sierra 18-3577 Marine Circulating Water Pump for GM Big Block 7.4L/454 - New

New Sierra 18-3577 marine circulating (freshwater) water pump, cast iron, long-style Big Block Chevy configuration. Application: GM 7.4L / 454 CID marine big-block engines including many OMC, MerCruiser, Crusader, PCM, Marine Power, and Volvo Penta big-block installations. Condition: New old stock — unused pump in worn original marine water pump box with shop tag showing Sierra P/N 18-3577 (WP-2231M). Buyer must confirm fitment by part number, photos, dimensions, engine model, serial number, and application before purchase.