Exhaust manifold replacement

[sierra09ny]

I have 2012 Sierra 2500HD with the gas 6.0 in it . The stock manifold on the drivers side is leaking , was curious what you guys went with for replacement on it , not looking to do headers just swap out the old one for a new one .I have here the dormer aren’t that well made , so figured I’d ask see if anyone has had any good luck replacing them ..ty 

[Ian Mills]

Just to clarify: The manifold itself is leaking?

A more common failure is the gasket between the manifold and the head. Replacing the gasket is definitely cheaper and easier than replacing the manifold

[newdude]

Is the manifold actually leaking?  Most common is broken bolts and bad gasket.  Many of them the manifold is okay, unless its really rusted.  

[swathdiver]

My choice would be another GM OE one.  When my gasket on the passenger side blew, the flange was warped and had to be sanded smooth again.  

[dna9656]

23 hours ago, sierra09ny said:

I have 2012 Sierra 2500HD with the gas 6.0 in it . The stock manifold on the drivers side is leaking , was curious what you guys went with for replacement on it , not looking to do headers just swap out the old one for a new one .I have heard the Dormer aren’t that well made , so figured I’d ask see if anyone has had any good luck replacing them ..ty 

I'm not sure if exhaust manifolds are still made the way they were back in the days of old, back then the opening of the manifold was smaller than the exhaust port on the head to quiet down the engine noise. When mileage didn't really matter much and gas was 35 cents a gallon no one cared except performance buffs. Tuned headers would be your best bet for performance and economy. I would reconsider your decision.

[sierra09ny]

23 hours ago, Ian Mills said:

Just to clarify: The manifold itself is leaking?

A more common failure is the gasket between the manifold and the head. Replacing the gasket is definitely cheaper and easier than replacing the manifold

 

so it’s leaking from where a bolt broke , I’m assuming the manifold is warped from heat so I was figuring I’d ask if anyone had good luck or saw any difference in manifolds from one to another if they had done the job .

[Ian Mills]

5 minutes ago, sierra09ny said:

so it’s leaking from where a bolt broke , I’m assuming the manifold is warped from heat so I was figuring I’d ask if anyone had good luck or saw any difference in manifolds from one to another if they had done the job .

Like Swathdiver said, it could be warped but in most cases you could have a passable solution with just new gaskets (and bolts in this case)

As far as replacing the manifolds, if I was going that route I would get some shorty headers that bolt up to my Y pipe.

[swathdiver]

JBL makes some shorty headers that actually gave a little more oompf to a buddy's Suburban.  I don't want the noise, sticking with cast iron manifolds.