Replace your leaking Duramax head gasket with this quality gasket from Grizzly. These gaskets are manufactured by Elring, a worldwide leader in gaskets. Elring is the OE supplier for many US automakers and aftermarket parts brands.
These head gaskets are the Grade C and have a installed thickness of 1.05mm.
Check with your engine builder or machine shop to verify head-gasket thickness requirements.
If your trucks apart for a gasket replacement, consider convert to DHD Chromoly head studs. Heads studs offer increased clamping ability and insure a long term leak free repair.