There are certain modifications in the diesel truck world that are more than just upgrades—they’re statements.
And perhaps no modification makes a louder, more unapologetic statement than a hood stack.
It’s a raw, visceral declaration of power that bursts right through the sheet metal. It tells everyone that this isn’t just any truck.
It’s a commitment to performance, sound, and a style that defines the peak of diesel culture.
But let’s be honest, cutting a hole in your hood is a big step.
You’re probably wondering if it’s all for show. What are the real performance benefits?
How do you choose the right kit for your Cummins, Power Stroke, or Duramax? What’s the difference between a 5-inch and a 7-inch stack?
This guide is your answer.
We’re diving deep into everything you need to know. From lowering your EGTs and improving turbo response to a play-by-play on the installation process.
1 Hood Stack vs. Bed Stack: Quick Comparison
For those on the fence, the choice often comes down to a hood stack or a bed stack.
Here’s a quick breakdown to help you decide which path is right for you and your truck.
| Feature | Hood Stack | Bed Stack |
|---|---|---|
| Performance | Most direct exhaust path, shortest travel. Potential for the lowest EGTs and fastest turbo spool. | Shorter than stock, but longer than a hood stack. Offers good performance gains over OEM. |
| Sound | Loudest possible setup. The sound is directed right at the cab. You hear every whistle and rumble from the turbo. | Very loud, but the sound originates behind the cab, making it slightly more tolerable for daily driving. |
| Installation | High difficulty. Requires precise measuring and cutting of the hood. Heat management is critical. | Moderately difficult. Requires cutting a hole in the truck bed. Less complex routing under the truck. |
| Practicality | Impractical for daily driving in rain/snow without a cover. Can obstruct vision slightly. Potential for soot on the windshield. | More practical. Keeps the exhaust and soot away from the cab and windshield. Less concern about rain. |
| Visuals | The most aggressive and head-turning look possible. A true “competition-style” statement. | A classic, powerful look that is very popular in the diesel community. A bit more traditional. |
| Verdict | For the hardcore enthusiast seeking maximum performance, sound, and visual impact, who is willing to sacrifice daily-driver convenience. | A fantastic, aggressive upgrade that provides great sound and performance with fewer daily-driving compromises. |
2 What is a Hood Stack? The Ultimate Diesel Statement Piece
So, what exactly is a hood stack?
At its core, it’s the most direct and efficient exhaust route you can create for a turbocharged diesel engine.
Instead of a long, winding pipe that travels the entire length of the truck to exit at the rear, a hood stack routes the exhaust from the turbocharger’s downpipe directly up and through a hole in the hood.
This isn’t just about re-routing a pipe.
It’s about fundamentally changing your truck’s respiratory system. Think of it like a sprinter taking the shortest possible path to the finish line.
That short, direct path is what unlocks the performance potential that gets diesel enthusiasts so excited.
3 Beyond Looks: The Performance Benefits of a Hood Stack
While the aggressive look is a huge part of the appeal, the performance gains are very real.
A hood stack is a functional modification rooted in the principles of diesel performance. It directly targets the enemy of every tuned diesel engine: high Exhaust Gas Temperatures (EGT).
By creating a path of least resistance for exhaust gases, you’re letting the engine breathe freely.
This efficiency has a cascading effect on the entire powertrain. From the engine block to the turbocharger itself, making it a popular mod for any performance diesel build.
4 Lower EGTs and Improved Turbo Response
The number one performance benefit of a hood stack is a significant drop in Exhaust Gas Temperature (EGT).
The stock exhaust system, with its long piping and restrictive muffler, traps heat and creates backpressure.
A hood stack practically eliminates that backpressure.
It allows hot exhaust gases to escape immediately. This keeps the engine cooler, which is crucial when you’re towing heavy or pushing for more horsepower.
This newfound efficiency also has a direct impact on your turbocharger.
With less backpressure to fight against, the turbine wheel in your Holset or BorgWarner turbo can spool up faster.
This means quicker throttle response and less turbo lag.
Your truck feels more athletic and responsive the moment you touch the pedal.
5 Hood Stack vs. Bed Stack: A Head-to-Head Comparison
The debate between a hood stack and a bed stack is a classic one in the diesel community.
Both modifications ditch the restrictive factory exhaust for a high-flow vertical exit. They deliver that iconic “big rig” sound and serious performance gains.
However, they offer very different experiences when it comes to installation, daily driving, and sheer auditory assault.
Choosing between them is about aligning the modification with your goals for the truck.
Are you building a dedicated sled-pulling monster or a daily-driven rig that still needs to be practical?
As we laid out in the comparison table, the hood stack is the undisputed king of raw, uncompromising performance.
The bed stack offers a more balanced approach.
6 A Buyer’s Guide to the Best Hood Stack Kits
Once you’ve committed to the hood stack life, the next step is choosing the right kit.
You’re not just buying a piece of pipe. You’re investing in the heart of your truck’s sound and performance.
The market is full of options.
Knowing the difference between materials, diameters, and tip styles is key to making a purchase you’ll be happy with.
From a universal kit for a custom Duramax exhaust project to a complete bolt-on solution for your Cummins, getting this choice right is crucial.
We’ll break down the key factors to consider. This ensures you get the perfect setup for your needs and budget.
7 Material Matters: Stainless Steel vs. Aluminized Steel
Your first major decision is the material.
The two primary options are T304 or T409 stainless steel and aluminized steel. The difference goes far beyond just looks.
It’s a classic trade-off between longevity and cost.
Aluminized steel is a budget-friendly option that gets the job done.
It’s strong and will last for a while. But it is susceptible to rust over time, especially in areas that use road salt in the winter.
For a truck that lives in a dry climate or isn’t a long-term keeper, it can be a smart way to save some money.
Stainless steel, on the other hand, is the premium choice for a reason.
Grades like T304 and T409 offer superior corrosion resistance. This means your stainless steel exhaust kit will look great and remain structurally sound for years, no matter the weather.
It costs more upfront.
But it’s a “buy it once, cry it once” investment in quality that pays off in the long run.
8 Choosing the Right Diameter: 5-inch vs. 7-inch Stacks
The diameter of the stack is another critical decision.
5-inch exhaust is the most popular and versatile choice. A 5-inch stack provides a massive improvement in flow over the stock system and is more than enough for the vast majority of trucks, even those with significant performance modifications.
It delivers a deep, clean tone and sharp turbo whistle.
So why would anyone go for a 7-inch stack?
Purely for aesthetics and sound. A 7-inch stack is all about making the biggest visual statement possible.
It produces an incredibly deep, hollow, and thunderous sound.
However, on most trucks, it can actually hurt performance slightly due to a loss in exhaust velocity. It may drone more at highway speeds.
Unless you’re running a massive, competition-level turbo, the 5-inch stack is almost always the superior choice for all-around performance.
9 Tip Styles Explained: Mitre Cut, Octagon, Bull Hauler
The final piece of the puzzle is the style of the tip.
This is all about personalizing the look of your truck. The most common style is the classic mitre cut, which is a simple angled cut that provides a clean, timeless, and aggressive look.
For those wanting something a bit different, you have options like the octagon tip.
It features eight flat edges for a unique, custom-fabricated appearance.
Another popular choice is the bull hauler (or turn out) style.
It features a curve at the top that helps direct soot and sound slightly away from the cab. The choice is purely cosmetic, so pick the one that best matches the vision you have for your truck.
10 Top 3 Hood Stack Kits for Your Diesel Truck
Choosing the right kit is the most critical part of your hood stack journey.
We’ve waded through the options, focusing on quality, performance, and value. These are the top kits for any diesel owner, from the seasoned fabricator to the weekend warrior.
Whether you’re working on a Power Stroke hood stack or a classic Cummins, these kits from trusted brands like Flo-Pro and MBRP offer the best starting points for your project.
11 1. Best Overall Kit: Flo-Pro Stainless Steel Hood Stack Kit
For the enthusiast who wants a high-quality, comprehensive solution without the guesswork, the Flo-Pro Stainless Steel Hood Stack Kit is the undisputed champion.
This kit provides everything you need, engineered to fit your specific truck model.
Flo-Pro is a legend in the diesel exhaust world for a reason.
They use high-quality T409 stainless steel that offers excellent longevity and corrosion resistance. This ensures your investment withstands the elements. The mandrel-bent tubing guarantees maximum flow, and the fit and finish are consistently top-notch.
When I first got my hands on the Flo-Pro kit, the first thing I noticed was the weight and quality of the stainless steel tubing.
The welds were clean and the components felt robust, designed for durability. In my field test on our shop’s Duramax, the installation was straightforward for a kit of this nature.
The result was an immediate, noticeable drop in EGTs under load and a turbo whistle that was crisp and clear.
12 2. Best for Custom Fabricators: Universal 5″ Turbo-Back Kit
If you’re a welder or a builder who prefers to chart your own course, a universal kit is your blank canvas.
These kits provide the essential building blocks—lengths of pipe, bends, and a stack tip—leaving the final routing and fabrication up to you.
This approach gives you complete control over the final product.
It allows you to create a truly one-of-a-kind custom exhaust. It’s the perfect choice for non-standard engine swaps or for builders who want to tuck the exhaust piping in a very specific way.
For a project like this, your control over the weld is paramount.
This starts with your electrode holder. Read our guide on choosing the best welding stingers to ensure you have the grip and reliability needed for this demanding job.
You’ll be working with high-quality stainless steel, and you can’t afford a mistake.
A premium carbon fiber welding hood provides the clear view and lightweight comfort needed for this level of fabrication.
13 3. Best Budget-Friendly Option: A Quality Aluminized Steel Kit
Want the aggressive sound and performance of a hood stack without the premium price tag of stainless steel?
A quality aluminized steel kit, often available from brands like Diamond Eye or MBRP, is an excellent choice.
Aluminized steel provides the same performance benefits—lower EGTs and improved turbo response—at a fraction of the cost.
The main trade-off is longevity. It won’t resist rust and corrosion as well as stainless steel, making it better suited for drier climates or for builds where budget is the primary concern.
Even as a budget option, these kits deliver that signature soot life culture and sound.
It’s a fantastic way to get into the hood stack game and see if it’s right for you without a massive financial commitment.
14 The Installation Process: What to Know Before You Cut
Let’s be clear: installing a hood stack is a serious, permanent modification.
This isn’t like bolting on a cold air intake. It requires confidence, the right tools, and careful measurement.
A project of this magnitude requires safety and precision.
Ensure you have all the essential welding gear and PPE before you begin.
The reward is immense, but the “measure twice, cut once” mantra has never been more critical.
Once you cut that hole in your hood, there’s no going back.
15 Tools Needed for a Hood Stack Installation
Having the right tools ready will make the difference between a frustrating weekend and a successful installation.
Here’s a basic list of what you’ll need:
A quality welder (MIG or TIG). Angle grinder with cutting and flap discs. A metal-cutting hole saw (sized to your pipe diameter).
Power drill. Measuring tape and markers. Complete socket and wrench set.
Safety glasses, gloves, and hearing protection. High-temperature paint or primer for the cut edge.
16 The Point of No Return: Measuring and Cutting the Hood
This is the moment that separates the talkers from the doers.
First, assemble the downpipe and lower portion of the stack under the hood. Make sure it clears all engine components. Use a plumb bob or laser to mark the exact center point on the underside of the hood.
Drill a small pilot hole from the bottom up.
Now, close the hood and, from the top, use your hole saw to make the final cut. Go slow, use cutting oil, and let the tool do the work to ensure a clean opening.
17 Critical Step: Heat Management
One of the most overlooked aspects of a hood stack installation is heat management.
The exhaust pipe coming off your turbo can reach temperatures exceeding 1,200°F. It’s now routed through an engine bay filled with sensitive components.
Properly shielding your new exhaust is not optional—it’s essential for safety and reliability.
Use high-quality exhaust heat wrap around the pipe sections that are close to wiring harnesses, fuel lines, or plastic components.
In some cases, fabricating a small metal heat shield can provide an extra layer of protection and peace of mind.
FAQ: Your Hood Stack Questions Answered
You’ve got questions, and we’ve got answers.
This section tackles the most common queries and concerns we hear from diesel enthusiasts considering a hood stack.
Do hood stacks add horsepower?
This is a common question, and the answer is nuanced.
A hood stack itself doesn’t directly add horsepower in the same way a larger turbo or injectors do.
Instead, it unlocks horsepower potential.
By drastically reducing backpressure and lowering EGTs, a hood stack allows your engine to run more efficiently and safely. This means your existing performance tune can work better, or you can tune your truck more aggressively without risking engine damage from excessive heat.
So while it’s not a direct horsepower adder, it’s a critical supporting modification for any high-performance diesel truck exhaust system.
Are hood stacks illegal?
The legality of a hood stack is complex and varies significantly by state and local regulations.
In many areas, any modification to the factory exhaust system that makes it louder than stock can be illegal.
More importantly, if installing the hood stack involves removing federal emissions equipment like the Diesel Particulate Filter (DPF) on a modern truck, it is a violation of federal law for any vehicle operated on public roads.
As for “rolling coal,” this is a product of excessive fueling from an aggressive engine tune, not the stack itself.
This practice is illegal in most places and can result in hefty fines. Always check your local laws before modifying your custom exhaust.
How do you keep rain out of a hood stack?
This is the most practical concern for any hood stack owner.
Since the exhaust is pointed straight up, rain and snow can get directly into your exhaust system and potentially your turbocharger.
The most common solution is a simple flapper cap that closes when the truck is off and opens from the exhaust pressure when it’s running.
Another option is to use a “bull hauler” or turn-out style tip.
For parked trucks, many owners simply place a coffee can or a dedicated rain cover over the tip to keep water out.
How much does it cost to have a hood stack installed?
The cost can vary dramatically based on whether you do it yourself or hire a professional shop.
If you’re tackling the project yourself, your main costs will be the kit itself. This ranges from $250 for a basic aluminized kit to over $600 for a premium stainless steel exhaust kit. Plus any tools you need to buy.
If you have it professionally installed, you’re looking at the cost of the kit plus labor.
Labor can range from $400 to over $1,000, depending on the shop’s rate and the job’s complexity. A custom fabrication will always cost more than installing a pre-made kit for a common truck like a Cummins hood stack.
