Duramax Head Gasket job Add-On

Your head gasket is blown and you have the heads off of your 2001-2010 Chevy 6.6L Duramax engine. No one likes to have their truck in the shop and not on the road, so why not upgrade your engine while the heads are off. Since taking the heads off of your motor is not an easy job, replacing an exhaust manifold is not something that one would ordinarily do without having other motor work done at the same time. So for all you 2001-2010 Duramax owners, next time you have a head gasket job going on, definitely think about replacing your exhaust manifold.

On 2001-2010 6.6L Duramaxs, the factory driver’s side exhaust manifold is pinched to allow for steering shaft clearance. Since the manifold is pinched, there is significantly less airflow in two cylinders on the driver’s side when compared to the passenger side. With only 80% of the airflow on the driver’s side compared to the passenger’s side, there is an imbalance, especially in heat build up, between the two sides of the engine.

So your heads are off and you want to replace your exhaust manifold but don’t know what to buy. Some aftermarket companies may offer exhaust manifolds that increase the internal bore size of their units. Usually these bored out exhaust manifolds have larger internal bore sizes than the port size on the cylinder head. While these exhaust manifolds may cool the exhaust inside the actual manifold, they do not cool temperatures in the combustion chamber because there is less turbo boost. This affects engine performance by lowering turbo drive pressure energy and gives false EGT temperatures.

The Full Bore Exhaust Manifold from BD Diesel restores exhaust flow balance, improves power and reduces EGT’s in the combustion chamber of your engine. Remember how we said that the factory manifold is pinched, which led to these exhaust deficiencies and heat issues? Well the pinching of the manifold is not actually needed, there is enough existing room in the engine compartment to allow for steering shaft clearance. BD’s exhaust manifold is not pinched, which means that internal bore size can be maintained. A uniform internal bore size means a uniform, steady turbo drive pressure!

Constructed out of high silicon ductile iron, this exhaust manifold from BD is a direct, bolt-on replacement for factory manifolds. The BD manifold even comes drilled and tapped to accept the most popular EGT probes. 

So the next time you have you heads off for a head gasket job, make sure to replace the exhaust manifold. Since the heads are already off and the BD manifold is a direct replacement, there is no labor involved in this job.

Comparison of OEM manifold vs. BD manifold

Comparison of OEM manifold vs. BD manifold


What's up everyone! Welcome to our new website! Starting in 2003, we have progressed from a small shop in to an 8,000 square-foot shop equipped with five lifts, an alignment machine and a bunch of tools/machines that help us to be one of the premier performance shops in the Northwest.

Due to difficulties with our old website, dunksperformance.com, we have created dunksbuilt.com! Dunksbuilt.com is meant to be an online extension of what we embody at our shop. We are performance specialists, especially when it comes to diesel, off-road and LSX performance.  The products we offer on this site will only be products that we have used, installed and recommend.

We hope to offer insight to customers who are looking to learn more or just like the work we do. We will use our blog to share information, insight and recommendations. At Dunks Performance we aim to be at the top of our industry when it comes to the products we offer and the knowledge we possess. Everything we do is #DunksBuilt, something that we are very proud of!