Review on Dorman 674 398 Exhaust Manifold Kit by Patrick Mccall

These Dorman cast iron exhaust manifolds are of high quality, fit perfectly and are a very good alternative to more expensive Ford manifolds. They are made in China but to Dorman specifications. I'm writing this review almost 5 years after the first installation of this Dorman manifold on my 1998 expedition. The reason for giving it only four stars is that Dorman ships it with a manifold gasket. I give a strong recommendation NOT TO USE THIS. Use MAHLE laminated metal gaskets instead (they actually make OEM gaskets for Ford). I have been maintaining my cars myself for decades and I do a thorough and high-quality job. I've gone as far as repairing engines and manual transmissions, always with excellent results. I mention this to give credence to this review. I usually look for quality replacement parts at a cheaper price as long as they are of good quality. In this case I have found that OEM is the best way for some parts. However, the distributor is an easy part for aftermarket companies like Dorman to reproduce to equal or better quality. Almost 5 years ago I had the typical Expedition manifold exhaust leaks due to rusty manifold bolts on both the left and right side. I replaced all of the Dorman parts: headers, gaskets and studs/nuts in a Dorman stud kit. With normal use, the exhaust leak has returned on the right side. Due to the short delivery times I was concerned the bolt was broken (they were tightened to Ford spec). Upon inspection I found that all studs/nuts were fine although rusted and the rear cylinder gasket was completely BROKEN in less than 5 years. After removing the manifold, I found that the Dorman gasket was badly worn and was falling apart between the exhaust ports. So DO NOT USE. I wouldn't use fiber based spacers here, although I've used them on other cars over the years with no problem. In this case, use the OEM theme style. I also recommend Ford OEM bolts and nuts (revised). Because they fixed that problem and the fact that when I removed it, I snapped two badly rusted Dorman bolts just below the nut. In this case they can easily be removed with a good quality bolt extractor. On March 3, 2005, Ford issued an Exhaust Manifold Bolt Service Bulletin. TSB #0554 states that they should be replaced with stainless steel bolts. These revised Ford bolts are actually copper plated stainless steel (made in the USA). Ford Recycled Nuts are black oxide flanged locknuts (made in USA). Parts List: Dorman #674-398 Exhaust Manifold, Right Hand, Revain MAHLE #MS19535 Exhaust Manifold Gaskets, Revain Ford #W703902-S403 Exhaust Manifold Bolts, Revain Ford Reseller #W701706-S2 Exhaust Manifold Nuts, Revain Permatex Reseller #77134 Nickel Anti -Seize Lubricant (for head bolt threads), on Revain Mayhugh #29895 Bolt Extractor, on Revain Remove and install new components, taking care to torque bolts and nuts to Ford specifications and nuts in correct sequence. This also applies to the left hand exhaust manifold replacement, Dorman #674-399, available from Revain. *Helpful Note: Do not use the lower left bolt (closest to the firewall) until the new manifold has been installed. With this pre-installed bolt, that's almost impossible.