Which Exhaust Manifold Should I Buy

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The drivers side manifold is a Dorman one that's been on for 10 years. My father paid the dealer to change it, assuming that it would get OEM parts. But it got a Dorman one with a Motorcraft price.

Originally Posted by atikovi
What happens if the studs or bolts snap? A 1 hour job turns into 8. Unless it's really loud, can't you live with it?


It's not the noise. It's the 20-30% fuel trim on that bank that I don't care for. It gets very confused when it hits closed loop and the gas mileage is single digit.

But it's going to a mechanic. This is way above what I can tackle.
 
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I just took a junk Dorman manifiold off my 2008 F350 5.4.
Truck has 172k and previous owner already has put the dorman one on.
It has 2 small cracks in it, and the gaskets were total garbage, gaskets were falling apart and a piece of the gasket was actually laying on the frame under the manifold.
I put an OEM manifold on it, it was an improved design kit, that came with nice stainless multi layer gaskets, and new stainless studs and nuts.
I am confident the Ford part will last longer than the Dorman.
 
You can only hope. It is not a design issue it is the fender liners are too short and they get cold water thrown up on them. When old cast iron gets as hot as an exhaust manifold and gets a lot of cold water on it guess what happens eventually not matter who made it.
Extend the fender well liners to keep the water from the wheels getting thrown up on them and the problems don't happen.
 
Originally Posted by Trav
You can only hope. It is not a design issue it is the fender liners are too short and they get cold water thrown up on them. When old cast iron gets as hot as an exhaust manifold and gets a lot of cold water on it guess what happens eventually not matter who made it.
Extend the fender well liners to keep the water from the wheels getting thrown up on them and the problems don't happen.


What fender liners ? Super duty trucks didn't have them on 01 haha
 
Is it open in there to the engine compartment? This has front leaf springs and a long shock? You may have to place it from inside, I don't have one to look at. Look for body/frame gap fillers, the ones for old Ford F150 97-2001 are huge and can probably be cut to fit the F350.
 
Completely open. Definitely wasn't a thought for them and the cause that these trucks always have one or more cracked manifolds.

It's leaf sprung with the big shock, correct. Not the torsion bar and mini shock like the f150s had.
 
When something fails like these manifolds regardless of what part of the country they are in and so my vehicles it is usually something more than just crap parts.
The stainless stud kit TSB is a band aid for a greater issue.
Mechanics change parts but most of them don't think or care about why they failed, yes there are a rash of bad or substandard parts but over so many similar models over that many years with the frequency these have it has to be more than that.

The 1970 Ford LTD had a rash of cracked exhaust manifold failures on the 351 r/side IIRC. The previous years and the 71 model had extensions that sat down on top of the UCA and didn't have the issue.
That and the fact the failures happen mostly on the passengers side which is close to the wheel well is what brought be to try it on a 99 F150 over 12 years ago when I swapped the manifolds, it has had no further issues, the manifolds still look like iron not hunks of rot hanging on the heads and the studs (not stainless) still look like studs with threads and not rotten needles.
 
I may try to make something. I certainly have enough pieces of various thin metal or aluminum hanging out.

The rest of the truck is so rusty I try to avoid driving it in the salt any more. I'm afraid i'll have two separate half trucks if I drive it in the salt.
 
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