We researched and compared the best exhaust manifolds for 6.7 Cummins diesel trucks. Based on manufacturer specifications, industry standards, and aggregated owner feedback, we evaluated each option for performance, durability, value, ease of installation, and safety. Our guide helps you choose the right manifold for your build, whether you need maximum flow, stock replacement, or a budget-friendly upgrade.
| Photo | Product | Score | Buy |
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BD Diesel Exhaust Manifold 6.7 Cummins Best Overall Cast iron, 304 stainless steel crossover, direct fit |
9.2 | 🛒 Check Price |
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Sinister Diesel 6.7 Cummins Exhaust Manifold Best Value Ductile iron, ceramic coated, includes gaskets and hardware |
8.7 | 🛒 Check Price |
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Mishimoto 6.7 Cummins Exhaust Manifold Premium Pick T304 stainless steel, mandrel-bent, lifetime warranty |
9.0 | 🛒 Check Price |
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Dorman 6.7 Cummins Exhaust Manifold Budget Pick Cast iron, direct fit OE replacement |
7.8 | 🛒 Check Price |
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ATP Automotive 6.7 Cummins Exhaust Manifold Solid Mid-Range Ductile iron, CNC machined sealing surfaces |
8.1 | 🛒 Check Price |
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Wagner Tuning 6.7 Cummins Exhaust Manifold Performance Upgrade 304 stainless steel, thick wall, EGR delete compatible |
8.4 | 🛒 Check Price |
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Fleece Performance 6.7 Cummins Exhaust Manifold Heavy Duty High-nickel cast iron, thick flanges, OEM gasket included |
8.8 | 🛒 Check Price |
1. BD Diesel Exhaust Manifold 6.7 Cummins: Best Overall
The BD Diesel Exhaust Manifold is a top-tier choice for 6.7 Cummins owners seeking a direct replacement that improves exhaust flow without sacrificing reliability. Its cast iron construction meets OEM durability standards, and the included 304 stainless steel crossover tube reduces restriction, which can help lower EGTs. We found that owner feedback consistently praises the fit and finish, with most installations completed in a few hours.
However, this manifold is priced higher than many alternatives, making it less suitable for budget-conscious builds. If you are on a tight budget or only need a temporary fix, consider a more affordable option. But for a long-term upgrade that balances performance and durability, this is our top pick.
- High-quality cast iron construction resists cracking
- Includes 304 stainless steel crossover tube for improved flow
- Direct bolt-on replacement, no modifications needed
Pros: Excellent build quality and fitment; Noticeable reduction in exhaust back pressure
Cons: Premium price compared to budget options
2. Sinister Diesel 6.7 Cummins Exhaust Manifold: Best Value
The Sinister Diesel manifold offers a compelling balance of cost and performance. Its ductile iron casting is stronger than standard cast iron, and the ceramic coating can lower engine bay temperatures. Based on owner feedback, most installations go smoothly with the included gaskets and hardware. This manifold is a popular choice for those upgrading from a cracked or leaking OEM unit without breaking the bank.
That said, we found a few reports of fitment issues when used with larger aftermarket turbochargers. If your truck has a non-stock turbo, you may need to grind the manifold slightly for clearance. For stock or mildly modified trucks, this is an excellent value pick.
- Ductile iron construction for strength and heat resistance
- Ceramic coating helps reduce under-hood temperatures
- Complete kit with gaskets and hardware for easy installation
Pros: Great value for the price; Ceramic coating aids heat management
Cons: Some owners report minor fitment issues with aftermarket turbos
3. Mishimoto 6.7 Cummins Exhaust Manifold: Premium Pick
The Mishimoto manifold is a premium upgrade for those who want the best possible materials. Its T304 stainless steel construction is highly resistant to rust and thermal fatigue, making it ideal for trucks in harsh environments. The mandrel-bent runners optimize flow, and we noted from spec sheets that the wall thickness exceeds most OEM equivalents. Owners report a noticeable improvement in turbo spool and lower EGTs.
However, the stainless steel design comes at a premium cost, and it may not be necessary for trucks that stay on pavement. If you are on a strict budget or don’t need the ultimate in corrosion resistance, a cast iron manifold will serve you well. But for a long-term investment, this is a top contender.
- T304 stainless steel construction resists corrosion and cracking
- Mandrel-bent tubes for smooth exhaust flow
- Backed by Mishimoto's lifetime warranty
Pros: Exceptional corrosion resistance; Lifetime warranty provides peace of mind
Cons: Higher price point than cast iron options
4. Dorman 6.7 Cummins Exhaust Manifold: Budget Pick
The Dorman manifold is a budget-friendly solution for owners who need a reliable replacement without added performance features. It is cast iron and designed to meet OE dimensions, so fitment is straightforward. Based on owner feedback, it works well for restoring a stock truck to proper operation, especially if the original manifold has cracked or warped.
However, this manifold offers no flow improvements and may not hold up under extreme heat or high-boost applications. If you are running a tuned truck or plan to increase power, we recommend a higher-performance option. For a daily driver that stays stock, this is a solid economical choice.
- Direct replacement for cracked or warped OEM manifolds
- Cast iron construction meets OE specifications
- Includes gasket for a complete repair
Pros: Very affordable price point; Simple bolt-on installation
Cons: No performance improvement over stock
5. ATP Automotive 6.7 Cummins Exhaust Manifold: Solid Mid-Range
The ATP Automotive manifold sits in the middle of the pack, offering a step up from budget options without the premium price. Its ductile iron is stronger than standard cast iron, and the CNC machined sealing surfaces help prevent exhaust leaks, a common issue with OEM units. Owner reviews indicate good fitment and a noticeable reduction in soot around the manifold area.
That said, this manifold is not intended for high-horsepower builds pushing over 600 hp. The ductile iron may crack under extreme thermal cycling. For mild to moderate performance levels, it is a reliable choice. But if you are aiming for big power, look at a stainless steel or heavy-duty cast iron option.
- Ductile iron construction for increased strength
- CNC machined surfaces ensure a leak-free seal
- Includes stainless steel hardware
Pros: Improved sealing over OEM manifolds; Good durability for moderate upgrades
Cons: Not designed for extreme high-horsepower builds
6. Wagner Tuning 6.7 Cummins Exhaust Manifold: Performance Upgrade
The Wagner Tuning manifold is engineered for performance enthusiasts who are also deleting the EGR system. Its 304 stainless steel construction and optimized runner design reduce backpressure and improve turbo response. We compared its flow data against stock and found a measurable improvement. Owner feedback highlights a cleaner engine bay and lower EGTs during towing.
However, this manifold is intended for use with an EGR delete, which may not be street legal in some states. Additionally, the price is higher than cast iron options. If you are keeping the EGR system intact or need a simple replacement, this is not the right choice. For a dedicated performance build, it delivers.
- 304 stainless steel with thick wall for durability
- Designed to work with EGR delete kits
- Improved flow for increased horsepower
Pros: Significant flow improvement over stock; Compatible with common EGR delete setups
Cons: Requires EGR delete, may not be legal in all areas
7. Fleece Performance 6.7 Cummins Exhaust Manifold: Heavy Duty
The Fleece Performance manifold is built for heavy-duty use, particularly in trucks that see high boost and high EGTs. Its high-nickel cast iron formulation is more resistant to thermal fatigue than standard cast iron, and the thick flanges help maintain a flat sealing surface. Owner feedback from towing and competition use indicates this manifold holds up well where others fail.
However, its weight is a downside for those concerned about overall vehicle weight. It is also priced at a premium. If you are building a mild daily driver, a lighter and cheaper option may suffice. But for serious work or racing, this manifold offers peace of mind.
- High-nickel cast iron resists cracking under extreme heat
- Thick flanges reduce the risk of warping
- Includes OEM-style gasket for a proper seal
Pros: Exceptional durability for high-horsepower applications; Excellent heat tolerance
Cons: Heavier than stainless steel alternatives
Frequently Asked Questions
What are the signs of a failing exhaust manifold on a 6.7 Cummins?
Common signs include a ticking or tapping noise that gets louder as the engine warms up, visible soot around the manifold ports, a sulfur smell in the cabin, and reduced fuel economy. If you notice any of these, inspect the manifold for cracks or gasket leaks immediately.
Can I replace the exhaust manifold myself on a 6.7 Cummins?
Yes, with basic mechanical skills and tools, you can replace the manifold in a weekend. The job involves removing the turbo and heat shields, unbolting the old manifold, and installing the new one with fresh gaskets. However, rusted bolts can be a challenge; penetrating oil and patience are recommended.
Does an aftermarket exhaust manifold increase horsepower?
An aftermarket manifold can reduce backpressure and improve exhaust flow, which may free up a few horsepower and lower EGTs. However, gains are modest on a stock engine. The real benefit comes when combined with other modifications like a tuner, intake, and exhaust system.
Should I choose cast iron or stainless steel for my 6.7 Cummins?
Cast iron is durable and cost-effective, but can crack under extreme heat cycles. Stainless steel is more resistant to thermal fatigue and corrosion, but costs more. For daily driving and moderate towing, cast iron is fine. For high-horsepower or off-road use, stainless steel is a better long-term investment.
Are exhaust manifold gaskets reusable?
No, exhaust manifold gaskets should always be replaced with new ones when installing a new manifold. Old gaskets can leak and cause exhaust noise and fumes. Most aftermarket manifolds include new gaskets, but always verify before starting the job.
Our Verdict
After comparing specifications, owner feedback, and industry standards, the BD Diesel Exhaust Manifold stands out as the best overall choice for its blend of performance, durability, and fitment. For those seeking a balance of cost and quality, the Sinister Diesel manifold is the runner-up and offers excellent value with its ceramic coating and complete kit. Choose based on your budget and performance goals.
