2001-2016 Duramax Billet Exhaust Manifolds

Factory Duramax cast manifolds are a known restriction and crack/leak point once heat, mileage, and towing stack up. Wehrli’s billet set replaces both banks with TIG-welded, CNC-machined billet steel parts that are exhaust-port gasket-matched and internally divided for cleaner flow — quicker spool, lower EGTs, and a stronger exhaust path without requiring a tune.

This kit (WCF100363): 2001–2016 Duramax billet exhaust manifold kit finished in black ceramic coat (1800°F). Includes new manifold-to-head and manifold-to-up-pipe gaskets, ARP 12-point head fasteners with washers and assembly lube, plus 1/8" NPT sensor ports (and plugs) on driver and passenger manifolds. Outlet geometry stays OEM-style so you can run factory up pipes now and step up to WCFab 2" stainless high-flow up pipes later.

Fitment gates:

• Fits 2001–2016 Chevrolet / GMC 6.6L Duramax — LB7, LLY, LBZ, LMM, and LML
• Parent/base manifold kit only — not a complete manifold + up-pipe combo (those are separate year-banded kits)
• Up-pipe fastener kits sold separately as WCF100240
• Common GM supersessions include 12637647, 12624683, 97224587 (confirm against your OE manifolds before order)
• Idaho Falls install help available when bay time allows

Shipping: This product cannot ship to California (same restriction as WCFab). Ships in its own box (~26 lb). Free ground over $150 excludes HI/AK.

Call 208-542-7793 with year, engine code (LB7–LML), and whether you already have (or want) WCFab 2" stainless up pipes.

Emissions-compliant performance only — Powertech Diesel does not sell deletes or defeat devices. Keep required emissions equipment where legally required.