Head Games

Installing Wagler Competition Products Cylinder Heads on an Lmm

- Chris Tobin

In the gasser community, bolting on a set of aftermarket cylinder heads is a great way to boost the performance of an engine, but on the diesel side of the fence there are not many aftermarket options. Wagler Competition Products designed replacement heads for Duramax engines that offer greatly improved airflow while bolting on just like a factory head. The heads are available in many configurations from basic stock replacements to wild CNC-ported and hand-blended units with oversize valves, custom springs and titanium retainers.

Here, we’ll show you the installation of a pair of Wagler “As-Cast” heads on a 2009 GMC Sierra 2500 HD with an LMM engine under the hood. We visited WCP’s shop in Odon, Indiana, and followed along to document the process as Jeremy Wagler performed the installation on Grant Adams’ GMC.

While Wagler was tearing into the Duramax engine, Adams decided he should make a few more upgrades at the same time—namely installing ARP head studs, Comp Cams beehive valve springs, 30% over injectors from S&S Diesel Motorsport and forged WCP push rods. The engine could have been put back together using the stock components, but it’s much easier to upgrade and replace these items while the heads are offthan to do it later. In addition to the upgraded components, a new gasket kit for the Duramax’s top end was necessary. Wagler prefers to use GM head gaskets and a Mahle gasket kit for the rest. A word to the wise:

Never reuse head gaskets as they will almost certainly leak and cause more headaches.