The OEM block off plate uses a gasket and can leak over time. The PPE billet block off plate is thicker and uses an O-ring seal. The O-ring is made from Viton more maximum longevity. The PPE billet block off plate installs using the OEM fasteners.
PPE GM 6.6L Duramax Coolant Block Off Plate-Billet Aluminum – Black – 119000820
$24.46