Cummins 3919806 Aftercooler Housing for 6BT 5.9L - Used

Used Cummins-style aftercooler housing, P/N 3919806, for the Cummins 6BT / 6BTA 5.9L inline-six diesel in marine and industrial applications. Welded metal housing with top air-inlet flange and two side coolant ports; long bolt rail mates to the intake side of the block. Sold in used, un-tested condition — no visible cracks but internal core not pressure-checked. 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.