Aftermarket exhaust manifolds need advice

iowacornfarmer · Jan 24, 2017

So long story short I've got a rusty 97 F350 that needs a set of manifolds. I have the engine out now and already went through cutting each bolt off with a sawzall. Riff Raff has Ford ones for $384 per manifold, ouch. Dorman sells them and I've looked for reviews on them but all the threads are pretty old. Just wondering if they are worth trying for the huge price difference.

crcrawford87 · Jan 24, 2017

You could always buy the doorman and then take them to a machine shop and have them planed flat at the gasket surfaces.

iowacornfarmer · Jan 25, 2017

The only bad thing I've read is that they had cracking problems when torquing them down. Not sure if they ever fixed it or not.

co04cobra · Jan 25, 2017

Could just pick up a set of used Oem. I would not do dormans. I've removed cracked ones and seems like they never seal long term.

gnxtc2 · Jan 25, 2017

I am running a Dorman manifold on the passenger side for the past 4 years....no issues go far. I did not use the hardware that came with it. I used all OEM fasteners. The exhaust manifold bolts are a special design. I also decided to go with exhaust manifold gaskets. Int'l sells the gaskets. I torqued the exhaust manifold bolts to spec.

You really can't plane the manifolds as the angle changes. The up-pipes won't line up.

Billy T.
[email protected]

iowacornfarmer · Jan 25, 2017

co04cobra said:
Could just pick up a set of used Oem. I would not do dormans. I've removed cracked ones and seems like they never seal long term.

Where is the best place to find a set? I've checked eBay with no luck, everything local is rusted junk.

superpsd · Jan 25, 2017

Keep an eye on the west coast classifieds maybe. Things tend to last a long time without dropping salt everywhere. Car-Part.Com allows you to search wrecking yards for a specific part nation wide...