Dorman 03413B Exhaust Manifold Hardware Kit Compatible with Select Models

These exhaust manifold bolts are in good quality for the price. They fit perfect on my Jeep Wrangler JK. If you're doing your exhaust manifold, it is recommended to buy new set of bolts. These bolt are perfect fit. 5 star rating.

These manifold bolts worked perfectly for my 08 Trailblazer. Very good product.

Installed new bolts with no issues.

These are nice worked great would buy them again

Installed on '03 Trailblazer 6-popper 4.2L. All Trailblazer/Envoy/etc "Atlas" 4.2L DOHC engines should be similar. This was with the Dorman 674-777 exhaust manifold "Kit" for this vehicle.Received 12 bolts in the box as advertised. This application only needed 11, so this worked out well. Bolts were slightly shorter than originals--not enough shorter for me to care.Original bolts have thread-locking compound on them. Therefore, they're difficult to remove even after they're "loose". The thread-locking compound causes the bolt to turn hard all the way out. I dug out all traces of that chemical from the female threads in the cylinder head using a thread-cleaning "tap", and installed the bolts with anti-seize so they won't break next time they have to be removed.>>>TIP: Use a "universal-joint" socket to remove the old bolts, and DO NOT put side-pressure on the original bolts as you turn them. Side pressure will break the bolt shank even if the torque required to turn them doesn't.<<<Original bolts were Grade 9.8. These are 10.9. Should be stronger than the original bolts, but these are made in China, so quality grading is suspect.Flanged heads cover the oversized holes in the exhaust manifold.My Official GM service manual says 15 ft/lbs in one place, and 18 ft/lbs in another. I put them in at 15 ft/lbs using anti-seize as a thread lube.

Went in easy and no problems. If you take out the plastic wheel wells the job is much easier.

As described

These are a good fit for new header bolts. They fit my '06 SIlverado with a L33 5.3L engine just fine. I like how they are automotive grade hardened steel and coated to reduce rusting. However, i do think going OEM in this case would have been a better buy for 2 reasons. First, the OEM bolts come with a coating on the threads to help remove them in the future. Not really an issue as i always use anti-seize on my header bolts and all exhaust hardware. Second, and really by biggest gripe, is the head size of these bolts are smaller than OEM. These head size require a 12mm wrench and the OEM are 13mm. Now, 1mm isn't that much, but that's almost 10% smaller than original. I would much rather have the larger head size in order to apply more force to a bolt when removing it especially for part prone to rusting. Anyone who has broken a bolt in an engine, or in this case the heads, knows how much of a pain it is to remove. Also, a larger bolt head size would allow more "hold" force for the manifold to the engine. But again, i would prefer the larger head size bolt for ease of removal in the future.

Oil pressure gauge is functional again, installed on 03 silverado 1500hd 6.0L

Dorman, very good quality and a problem solver.

Replacement bolts for exhaust manifold to cylinder head. These fit exactly as expected. Save yourself the headache and replace the O.E. bolts with these bolts before they break off in the cylinder head.

Decent quality $100 less than GM.

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