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Discussion Starter #1
My manifold is leaking and starting to warp at 183K. I'd like to replace it before a bolt breaks off in the head. 2 or 3 piece manifolds used to be the consensus on 12 valve heads because the warpage could break off the ears on the head. Obviously that's not an issue on a 3rd gen head. I'm looking at the 2 piece DPS manifold and the AFE bladerunner 1 piece as they're the most affordable. Opinions on the benefits of a 2 piece for a 3rd gen?
 

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no experience with a 2 piece but the AFE SS Bladerunner I have has been solid as far as I can tell. I did have a broken exhaust manifold bolt on the #6 cylinder, next to firewall. No idea if the mani had anything to do with it, I suspect bad shocks on a dirt mtn road and not going slow had things bouncing a bit more then they should have been.
 

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no experience with a 2 piece but the AFE SS Bladerunner I have has been solid as far as I can tell. I did have a broken exhaust manifold bolt on the #6 cylinder, next to firewall. No idea if the mani had anything to do with it, I suspect bad shocks on a dirt mtn road and not going slow had things bouncing a bit more then they should have been.
Did you break the bolt with the AFE on or was that the previous manifold?
 

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it was with the afe and after 5 yrs of service... i have a thread where we discussed the bolt removal, pics r there and there was no manifold shrinkage. i have the SS one...
 

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The oem manifold was shrinking on my 03 HO and KT Performance had the best price on a 2 piece. I gasket matched all ports including the outlet and turbine housing on my II PS and it lowered my egt about 100 degrees. Get one! Craig
 

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2 piece manifold is a GREAT time to swap to 2nd gen design , good flow and get back the proper cummins sound that the 3rd gen manifold destroys .
 

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I'm worried mine are about to break since a few are visibly bent. I had a bolt break on my old 12valve and it took two days to get it out! I'm not really interested in the 2nd gen swap as I don't want to have to change a ton of stuff and my egts are never an issue in my usage.

I'm thinking I'll go for the 2 piece. Thanks for all of the replies!
 
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Even a new Cummins 3rd Gen exhaust manifold would work fine.
Cummins re-designed it a few times, adding material for greater durability.


There used to be tons of used aftermarket 2 piece 3rd Gen ex manifolds around as most guys go to a 2nd gen ex manifold when they go with a bigger turbo or twins.
 

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Heres another question- does anyone know if the Borg SXE-300 series turbos have any clearance issues with the 2 piece manifolds? The joint looks pretty hefty and like it might get in the way of a turbo in some situations.
 

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ENded up going with the DPS 2 piece. It's a very very nice piece. Definitely high quality and given it's the cheapest aftermarket manifold out there (other than the knock off ebay ones), I feel like it's a steal. I used stainless studs and nuts from purediesel power and a sure glad I did. I don't see how you can get the turbo on and off separately and turbo plus manifold is so damn heavy, it would be a huge PITA to try and use traditional bolts! I soaked all the old bolts in aero kroil for a week and sure glad I did. No bolts broke but dang, they were really close and the #1 cylinder holes needed some thread repair the old manifold was so warped!

Didn't notice any driveability changes. My Egts are never an issue. Maybe a little better boost, and less noise now that there is no leak!
 
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