Cummins 3921558 Engine Oil Cooler Core for 6BT 5.9 / ISB - Used

Used Cummins engine oil cooler core, stamped 3921558, for Cummins 6BT 5.9L / ISB 5.9L family diesel engines (industrial, automotive, and marine applications of that engine). Plate-fin bundle with integral mounting plate; appears complete and straight with normal service staining. Sold untested — buyer should pressure-test before installation. Buyer must confirm fitment by part number, photos, dimensions, engine model, serial number, and application before purchase. Used marine part sold as-is unless otherwise stated. No returns on electrical, used, special-order, or installed parts.