To help your 5.3 Silverado engine work with full efficiency, all you need is good-quality long tube headers! Also,quality-filled headers for 5.3 increase the engine’s horsepower and torque as the engine starts to attain good air airflow.
However, choosing the suitable 5.3L headers amongst wide variations of headers in the motor market can be tedious. To ease up your job, below we have reviewed the 9 best long tube headers for 5.3 Silverado to help you pick from, and enjoy a racing-speed engine’s benefits.
#What is The Best Long Tube Headers for 5.3 Silverado?
With its T304 steel build for maximum durability and strength, DNA Motoring HDS-GY99 Stainless Steel Exhaust long tube header is proven to be the best long tube header for 5.3 Silverado. The header’s mandrel tube-bending provides unlimited and unrestricted airflow for the engine’s smooth performance. Moreover, the 15.24 cm overall length makes this long tube header the perfect fit for 5.3 Silverado.
- DNA HDS-GY99 is made from T304 stainless steel for the longest possible use, which is tested. The metallic color finish boosts up your engine’s outlook too.
- Along with 5.3 Silverado, this header also supports 4.8L engines for equally unlimited exhaust gas reduction and lets your engine breathe.
- There comes bolts and gaskets inside the package for hassle-free installation. Moreover, the TIG precision welded CNC machine flanges enable tight-fitting in the outlet.
- This HDS-GY99 header has eight-cylindered stainless steel tube headers that allow maximum airflow to keep the engine’s performance and sound at a peak.
Quick Comparison: 9 Best Headers for 5.3 Silverado Trucks
|NAME & Details
|DNA Motoring HDS-GY99 Stainless Steel Exhaust Header
|BETTERCLOUD Stainless Headers For Silverado
|Gibson GP129S Stainless Steel Performance Header
|PaceSetter 72C2265 Performance Long Tube Exhaust Header
|Pacesetter 70-2266 Long Tube Header
|Kooks Custom Headers 28602401 Stainless Steel Headers
|Kooks 28602201 Header
|Patriot Exhaust H8059-1 1-5/8" Specific Fit Exhaust Header
|Silverado & Sierra 1 7/8" Long tube Headers
9 Best Long Tube Headers for 5.3 Silverado in 2022
1. DNA Motoring HDS-GY99 Stainless Steel Exhaust Header Manifold-Top-Notch Quality
The first header that takes its place in the list is the DNA motoring stainless steel header, which is built with scrutiny to meet your expectations from a long tube 5.3 tube header. This Silverado header also supports 4.8L engines equally to take out exhaust gas and let your engine breathe.
- Offers long-term engine support
- Metal gasket comes with the package for easy installation
- Increases engine horsepower and torque
- Works for 4.8L engines too
Airflow Restriction: The eight-cylindered stainless steel tube headers allow for maximum airflow to keep the engine’s performance and sound at a peak.
Material and Finishing: Material is highly durable T304 stainless steel for optimum strength and durability which is tested. The finishing is of a metallic color to boost up your engine’s outlook too. These 4.8 and 5.3L headers protect themselves from exterior harshness and do not have extra layers of coatings.
Length of the header: The length of the headers for 5.3 Silverado is a perfect fit with a 15.24 cm length.
Installation (cnc machined): There comes bolts and gaskets inside the package for installation. Moreover, the TIG precision welded CNC machine flanges enable tight-fitting in the outlet. However, those who don’t know the installation process, they should call a professional. Because no manual is included.
Permission on roads: Fortunately, this high-tech, durable long header has permission in all the states. You can easily mount it on your Chevy Silverado and enjoy it all over the US.
- Build from T304 stainless steel
- Has metallic color
- Inlet: 1.75 inches, Outlet: 2.25 inches
- Four cylinders from two-sides
It is one of the best 2003 Silverado headers. Besides that, it fits the below list.
- 1. 02-13 Chevrolet Silverado 1500 4.8 5.3 6.0 6.2
- 2. 07-16 Chevrolet Silverado 2500HD 3500HD 6.0
- 3. 2007 Chevrolet Silverado Classic 4.8 5.3 6.0
- 4. 2007 Chevrolet Silverado 2500HD Classic 6.0
- Super durable and lightweight
- Has 8 cylinders for constant airflow
- Improves engine’s HP and torque
- Tubings come mandrel bent for fast exhaustion flow
- No manual for installation instructions
2. BETTERCLOUD Stainless Headers For Silverado
These are some high-quality chevy 5.3 headers from BETTERCLOUD to keep on your list for the best long tube headers. The lightweight stainless-steel design provides ultimate support to your engine and has great durability to last long. Your engine will breathe free with increased horsepower once you place these headers in your vehicle.
- Goes well with Chevy 5.3
- Lightweight design for easy handling
- Increases engine horsepower
- TIG & MIG welded for good airflow
Airflow Restriction: The construction of T304 stainless steel provides maximum airflow to the exhaust and keeps cool and well-performing. The engine will never overheat with these headers, yet will operate with speed.
Material and Finishing: The material used is T304 stainless steel for long-time engine support. The stainless steel protects itself from corrosion too. Moreover, the CNC machine flanges have welded construction with TIG and MIG.
Length of the header: The basic tube size is 1.66 inches.
Installation: The headers already come with the required hardware for installation. However, there comes no instruction manual. So, if you don’t know, then hire a professional for help.
Permission on roads:This stainless header from BETTERCLOUD is not illegal in any state officially. It means, after buying it from an authorized seller, you can take full advantage of this header for your Silverado.
- T304 steel build
- Tube size: 1.66 inches
- Includes hardware inside the package
- Outlet size: 2.5 inches
It is the best header for 2004 chevy Silverado. However, it can fit a number of cars including the below list.
- Chevy Silverado 1500 1999-2006 4.8L, 5.3L(Except 2002 Chevy Silverado 1500 5.3L)
- Compatible with most of the Chevy GMC truck
- Made durably, yet lightweight
- CNC machine flanges are welded
- Includes all the installation hardware
- Installation requires professional hands
3. Gibson GP129S Stainless Steel Performance Header
To get the best out of the engine’s performance, no one can ever deny the contribution of the Gibson GP129S header. These long dyno-tuned tube headers for 5.3 engines are excellent to increase horsepower and make them breathe. These headers are compatible to use in both highways and streets.
- Increases engine Horsepower
- Keeps the engine cool and performative
- Exhaust Airflow remains constant
- Increases torque for low-range RPM
Airflow Restriction: The tube headers are built with 16-gauge stainless steel that enables the highest airflow for exhaust gas. It keeps your engine cool and breathable and always ready for superior performance.
Material and Finishing: Stainless steel ensures durability and helps to keep the tubes from rusting for a long time. There is no unprotected coated finishing which means there won’t be any peels coming off.
Length of the header: The tubing is 15/8 inches which is compatible with both high and low-raised vehicles.
Permission on streets: The Gibson stainless steel header is permitted and legal in 50 states of the USA.
Installation: Installing the dyno-tubes is not a tough job as Gibson already provides all the required hardware for placement. Moreover, they are replaceable with any factory-style header. So, if you know about installing a factory header, then that will be enough.
- Made of 16-gauge stainless steel
- Dyno-tuned header
- Permeable in 50 states
- Meets EPA requirements
If you’re looking for the best 2003 Silverado long headers, then it will be your great choice. However, it is also compatible with-
- 02-13 Chevrolet Silverado 1500 4.8 5.3 6.0 6.2
- 07-16 Chevrolet Silverado 2500HD 3500HD 6.0
- 2007 Chevrolet Silverado Classic 4.8 5.3 6.0
- 2007 Chevrolet Silverado 2500HD Classic 6.0
- Made for both low and raised vehicle engines
- Ensures better airflow and keeps the engine cool
- Easy installation with pre-packed hardware
- Replaceable with every type of factory header
- Very highly-priced
4. PaceSetter 72C2265 Performance Long Tube Exhaust Header
One of the great headers of 5.3 Silverado is the PaceSetter 72C2265 long tube exhaust header which has the reputation to make your engine’s performance and sound better. Pace Setter offers lifelong durability in its tube header at an affordable price to keep your vehicle’s performance at its best. Also, the installation of this tube header is effortless and fits properly on the 5.5 Silverado.
- Single-piece design makes easy installation
- Coated with Armor for long-lasting use
- Compatible for racing purposes
- All the hardware are included
Airflow Restriction: Airflow is unlimited as there are CNC-machine flanges in this tube header. The exhaust flow is continuous and sufficient which tends to improve the engine bay and its performance.
Material and Finishing: Unlike other traditional tube headers, the Pace Setter has a polished metallic ceramic coating that prevents rusting, discoloration, or peeling of the header and makes it long-lasting. The coating has 3 years of warranty to relish. Plus, the body of this Silverado 5.3 header is 16 gauge of carbon steel that ensures its longevity.
Length of the header: The tubes are 3/8 inches thick and 109 cm long that makes the perfect fit for your 5.3 Silverado.
Installation: Nothing is easier than installing the single-piece PaceSetter Silverado long tube headers. For users’ ease, the package already comes with the required hardware and gasket.
Permission on roads: This long tube header is not legal to use or sell in California and New York. Also, it is not legal to use in catalyst-equipped vehicles.
- 3-years of warranty
- 16-gauge metal tubing
- Bolt-on installation
It is one of the top 2004 chevy Silverado headers & also compatible with-
- 2007-2013 Chevrolet Silverado 1500, 2/4WD 5.3L
- 1999-2006 Chevrolet Silverado 1500, 2/4WD, AWD 5.3L
- Made of great quality material
- Has a protective external coating
- Offers excellent combustion
- Effortless installment with a one-piece design
- Comes with gasket
- Clamps are not good-quality
5. Pacesetter 70-2266 Long Tube Header for Chevrolet/GMC
Who said you need to spend extravagantly to upgrade your vehicle’s performance? All you need is Pacesetter long tube header, and this model is the perfect fit for your 5.3 Silverado with all the beneficial features. The glossy black headers will not only amp up the look of your engine but will also shoot up its performance while reducing backpressure.
- Tubings are Mandrel bent for fittings
- Improves engine’s outlook with a gloss-black paint finish
- Comes with a 3-inch volume collector
- One-piece build for easy handling
Airflow Restriction: Airflow is numerous with the 3/8 inches CNC-machine flanges, which allows exhaustive gas to pass out systematically. Besides, the once-piece design and mandrel-bent tubing push out the air sequentially. Hence, the cylinders can empty off well.
Material and Finishing: Pacesetter is always determined to provide highly durable tube headers for its customers. Hence, the long tube header for Silverado they made is of 16 gauges carbon steel. The outside has a glossy black finish that can make any boring engine look classy. The exterior also has protective armor coating to prevent peeling, rust and corrosion, and make it easy to clean.
Length of the header: The CNC-machine flanges have a thickness of 3/8 inches.
Installation: With the presence of fasteners and gaskets, this one-piece tube header is extremely easy to install. Handling for a few times will make it easier for you to re-install yourself.
Permission on roads: It does not have permission on roads of California and New York. That too, vehicles of the highest CA emission are strictly forbidden for this header.
- Built: 16-gauge carbon steel
- CNC-machine flanges are 3/8 inches thick
- Mandrel-bent tubes
- The package includes fasteners and a gasket
It is a top-notch 2004 Silverado long tube headers that also fits-
- 1999-2005 Silverado 1500 Base 5.3L V8
- 2004-2006 Silverado 1500 Hybrid 5.3L V8
- 1999-2006 Silverado 1500 LS 5.3L V8
- 1999-2006 Silverado 1500 LT 5.3L V8
- 2002-2006 Silverado 1500 WT 5.3L V8
- 2004 Silverado Z71 5.3L V8
- Easy to install and handle
- Made durable for long term use
- Has protected exterior
- Gasket’s volume collector is small
6. Kooks Custom Headers 28602401 Stainless Steel Headers
Another best-quality Silverado header is from Kooks which is built of highly durable 18-gauge steel for long-lasting performance. The 3/8 inches CNC-flanges make a perfectly sealed fit for 5.3 headers.
The precision added to the tube header ensures maximum airflow and keeps the engine cool while passing hot air. However, the tube headers are compatible with Kooks Y-pipe for better efficiency.
7. Kooks 28602201 Header
The seventh one is another model from Kooks made from the same 18-gauges stainless steel for years of robustness and crack-free performance. It is the best 2004 Silverado that provides unrestricted airflow by keeping the engine cool with the scavenger spikes on the collectors. Plus, there comes all bolts, screws, and gaskets inside the package for quick installation.
8. Patriot Exhaust H8059-1 1-5/8″ Specific Fit Exhaust Header
The Patriot 5.3 headers are made premium with yet again 18-gauge metal and comes in three varieties of external finishes. It is one of the top 05 Silverado headers that are 2/8 inches full-sized with a 2.5-inches collector.
Additionally, the metallic chrome finish keeps the engine temperature at control for better output. You can install the header by yourself with slight experience as it comes with gaskets and other hardware.
9. Silverado & Sierra 1 7/8″
The 2000 chevy Silverado 5.3 header is recommended for 6-speed transmission high-speed racings. The mandrel-bent tubes ensure sequential exhaust airflow to make your engine achieve additional horsepower. The 304 stainless built makes the tube last longer protecting itself from rust.
Best Headers for 5.3 Silverado Reviews 2021 – Buying Guide
Selecting 5.3 Silverado headers is a do-or-die situation. Because it is such an addition that can either improve or decline your vehicle’s engine’s performance. Therefore, choosing the right one with proper knowledge about long tube headers for Silverado is crucial.
To increase your vehicle’s performance, the engine needs to exhaust properly. That can only happen when you buy the tube headers that allow maximum airflow so that the engine can exhaust and breathe quickly. How freely tube headers exhaust airflow depends on their build quality. So, choose a wide header.
Material and Finishing
Material and finishing of the tube headers can tell about their longevity. If you don’t want to replace tube headers every month, which is time-consuming and costly, you have to spend on durably building ones with external protection included.
Carbon steel, stainless steel are considered robust, and having some sort of coating externally prevents the tubes from rusting and peeling.
Length of the header
The header length will determine your vehicle’s engine power. Short and compact headers are less efficient, so they do not let the engine move faster.
Whereas, longer tubes make the engine run quite fast and are good for high-speed racing. So, choose the length according to your need.
Permission on streets
Although it may sound invalid, some headers are not permitted everywhere because they enable high-speed driving. So, make sure the header you buy has permission to operate in your city.
The header installation is not tough at all. Moreover, they come with all the hardware and instructions for ease that someone who has basic knowledge can do it with ease.
However, before you buy the header make sure to check whether it fits the cavity made in your car or not.
Types of headers for cars- What are the different types of headers?
There are some different types of headers. Among them, “full-length” and “shorty” headers are most common. There are some general categories of headers – lakester style, full-length headers, shorties, and tri-Y.
The Two Types of Tube Headers (Manifolds)
Short Tube Headers
The short tube header is short compared to the long tube headers, but it has a much longer tube. The port pipes merge into the single exhaust pipe in a much shorter distance in the short headers. The 5.3 l headers, which are short, offer the best performance in the idle to the RPM range.
It makes the shorty headers the perfect headers for vehicles that rely on the low RPM range, such as the daily commuter or the work pickup that see a lot of hauling and towing. The short tube headers are designed to bolt right up with the exhaust that allows easily bolt in the set of headers without having to worry about the custom fabrication or having to move the stock emissions equipment like the catalytic converter.
The shorty header is appropriate for the turbo-boosted engine as well as it is perfect for the improved performance for the daily driver or the commuter. It is comparatively easier to install as it requires less space than the long tube.
The short tube header is fairly inexpensive. It is preferable only by using a turbo setup, but it can still be used in street builds and naturally aspirated engines.
Long Tube Headers
The exhaust pipe is much longer, and it merges farther out in the long tube headers. It makes lower exhaust backpressure, and the Chevy 5.3 headers improve oxygen intake as well as boost horsepower.
The full-length header makes a ton of power in the high RPM range to mid RPM range. But it is not necessarily street legal that depends on the emission standards. The installation process of the long tube headers for 5.3 Vortec is complicated.
The Silverado long tube headers are the best option for track terrors and high-rev vehicles. All extra space they require in the engine compartment demand some costly configuration.
The headers for 5.3 long tubes are generally considered the best to reduce the backpressure and scavenging. It typically flows less than the shorty headers.
The installation is more challenging as it is too long to work with the exhaust’s existing component. It is preferable only by using a non-turbo setup performance build as it produces higher performance numbers compared to its cost.
Pros and cons of headers
- The headers reduce the back pressure of the manifold.
- Headers improve the performance includes horsepower, fuel mileage, etc.
- 5.3l headers are great for the turbos.
- The exhaust headers enhance high revving.
- It increases the exhaust flow because of its smooth walls.
- The 5.3 Headers are usually lighter weight for the same size.
- It offers a better throttle response.
- Headers provide more mid-range and high-range RPM power.
- The header makes the car faster.
- Improved quality headers do not lead to a leak.
- The header makes a better appearance.
- It makes the tone of the car more precise.
- Header helps to clean up the bay of the engine.
- It provides getting rid of the ugly manifolds.
- The header offers the opportunity of running a giant exhaust pipe.
- Headers absorb less sound
- If the collector pipe is restricted, it is compromised.
- Header requires more cost.
- The header increased the possibility of burning the spark plug wires.
- It reduces the spark plug access.
- There tend to leak.
What headers do for a car?
For improving the performance of the engine, the header is one of the most comfortable bolt-on accessories. The aim of the header is making easier to push exhaust gases out of its cylinders.
The Silverado headers also make the car sound much louder. The ceramic-coated heater helps to keep the heat in the exhaust gas than the seep out.
It prevents leak speeds of heat, the expulsion of the exhaust out the tailpipe, and the headers improve the efficiency of the engine by decreasing backpressure. The headers are the most significant gains to the car. The exhaust heater reduces the back stress of the manifold.
One of the essential aspects of the smooth Silverado header installation is following the appropriate procedure to ensure the longevity of the gasket. If you want to ensure trouble-free sealing, you should make sure the gasket is made of a material that can withstand high temperatures and will be exposed.
Doug’s gaskets may ensure a trouble-free installation. Another essential issue for the leak-free operation is the way of installation of the header gasket. To install the gasket, you should follow the installation instructions.
You should make sure that the car completely cools down before starting the installation process and get ready with installation requirements. There has only one way to fit the lower gasket. The pattern of GM’s bolts is irregular. The professional installation of the gasket is recommended.
To install the headers, you should follow some steps, and these are the following –
- At first, you should install the headers and gasket, as well as you should tighten the bolts tight. Then you should run the engine and should allow the headers to get hot.
- After this, shut the engine down.
- When the header is still hot, you should again tighten the header bolts.
- Now you should run the car for 200 to 300 miles.
- When the header is still hot, you should one more time tighten the header bolts.
If you follow the procedure, the vehicle’s header bolts should stay tight, and the vehicle’s gasket should last several years. Rechecking the bolts is a good idea to make sure that everything is ok and remains tight.
Exhaust Headers vs. Manifolds
The exhaust manifolds generate back pressure that reduces overall performance because every cylinder has its tube. In contrast, a header reduces this problem because the headers allow the gas to exit without any backpressure.
Exhaust Headers are the alternative to using the exhaust manifold. Exhaust manifolds consisted of cast-iron and were included in the trucks and factory cars, whereas exhaust headers include stainless steel for every cylinder.
The exhaust manifolds are relatively inexpensive and easy to install, whereas headers are expensive and difficult to install. The exhaust manifolds can withstand the high pressure and heat associated with the gases.
The exhaust headers create noise as it is thinner than the exhaust manifolds. The exhaust manifolds reduce the engines’ efficiency and horsepower, while the exhaust headers increase the overall performance of the machine.
The exhaust manifolds materials cast iron are cheaper. Still, it is not the most robust material, whereas stainless steel is the exhaust headers’ material is the expensive but most vital material.
The main difference between the exhaust manifolds and the exhaust headers lies in their sound and performance. The exhaust manifolds have less space for passing gases, whereas the exhaust headers have more freedom.
The exhaust manifold absorbs more sound in contrast to the exhaust header, which absorbs less sound.
What is 5.3 long tube headers hp gain?
The 5.3 l long tube headers gain an average of 15 to 20 hp. Almost all the headers provide equal horsepower, but some of the headers offer better than the other headers. They may differ by less than 10 hp.
Do headers add horsepower?
Usually, a good set of headers provides a 10 to 20 increasing rate of horsepower. It also can increase the fuel mileage by restraining the right foot.
The improvement of power depends on the design of the camshaft, cylinder evacuation head ports, intake exhaust system, and the restrictiveness of the stock exhaust manifolds.
The aftermarket headers add almost 4 hp on their own, which broadened the car’s power curve. The header removes the exhaust, and there is a surplus of clean air that allows the engine to increase horsepower production.
The long tube headers 5.3 Silverado help burn the gasoline in the cylinder and expand during the stroke that generates power.
Is it illegal to put headers on a car?
The header is not always illegal; some of the cars come stock with them. Most of the short tubes are regarded as legal in most countries.
Header not only makes the car louder but also considered tampering with the vehicle emissions. If the vehicle is newer than the 1971 model, it will not be able to run open header at the street for any reason.
Since federal pollution standards took effect in 1972, passing untreated exhaust gases through the catalytic converter on every car made that year or later is illegal.
Are headers bad for your engine?
The headers do not harm the engine. It could end up losing a little bit of the torque and gaining horsepower. Usually, the aspirated engine needs some of the exhaust back pressure to function correctly.
The header allows the gases of the machine to exit without putting back pressure. The header improves the overall performance of the engine.
How much HP does long tube headers add?
The long tube headers developed the top power output from 407 horsepower to 434 horsepower, and the top torque leaped too, from 417 lb-ft. to 438 lb-ft.
You will also like the outcomes of the torque offered by the down-low headers. Usually, a set of long tube headers yield 20 to 30 horsepower without other changes on the vehicles with a single stock exhaust system. The hooker headers can increase in torque and power which will rise from 3000 rpm to 6000 rpm.
Are long tube headers louder than shorty headers?
When you will have a comparison to your stock exhausting manifold, then you will find the shorty headers will have a longer tube.
If your header’s length is unequal, then it will offer a disturbing sound with a little low-end torque. But if your header’s length is equal, then it will offer great and consistent performance gains.
Are long tube headers worth it?
Yes, long tube headers are worth every penny because they have an advantage that will not only provide peak power numbers but also help you to increase torque and horsepower at the same time in the mid-range and low range of the RPM band. It will give you more utilized power down where you most require it.
Do long tube headers add horsepower?
Long tube engines have around 16 more horsepower. This was accomplished by modifying the camshaft and heads of a 4.8L LR4 engine.
You may expect approximately 443 horsepower with long tube headers, as the engine generated 427 horsepower at 7,000 rpm after modifications.
What Size Long Tube Headers Should I Get?
Nonetheless, Don recommends the following for a street car: 400–500 horsepower select 1 3/4–2 inches, 200–325 horsepower select 1 1/2-inch primary, 275–425 horsepower select 1 3/4–1 7/8 inches, and 500+ horsepower select 2 inches or more.
How Much Horsepower Does Long Tube Headers Add To A V8?
A set of long tube headers on an American V8 engine can often add 20 to 30 horsepower to a vehicle with a factory exhaust system. Typically, ECU retuning is required while using headers.
What Headers Give The Most Horsepower?
Thanks to medium and long-tube headers, an engine can generate more horsepower at high rpm. The 4-into-1 header is a popular long-tube header consisting of four primary tubes that have been bent and directed into a single collector.
Who Makes The Best Headers For A Chevy?
There are a number of companies that produce headers for Chevy vehicles. Some of the more popular brands include Borla, Magnaflow, and Flowmaster. It really depends on your personal preferences as
Do I Need A Tune For Long Tube Headers?
Yes, you must tune your vehicle after installing a new exhaust header. Major performance adjustments, such as a header, can dramatically alter crucial metrics, such as the air-to-fuel ratio. Tuning is required to maximize the performance of the header without causing further complications.
Do Long Tube Headers Turn On Check Engine Light?
Long tube headers almost always activate the engine’s check engine light. If tuners are available in your area, the rear O2 sensors can be easily disabled.
What’s Better Long Tube Or Shorty Headers?
All headers attempt to flow exhaust more quickly and effectively. Long tube headers equalize exhaust pulses, which increases torque.
Since they take the place of factory manifolds, shortys are simpler to install. Routing long tubes takes time and effort.
Are Headers Worth The Money?
Headers are undeniably valuable, both for their sound and their benefits. To larger, click Get your reasoning out of here, guy. As long as they are selected appropriately for the application, headers might be advantageous.
At the end of it, now you must have known some of the best Silverado 5.3 long tube headers. Now it’s time to give your Silverado engine some boost of energy it deserves. No matter which one you buy, make sure that it is durable with good airflow and meets some of the other requirements mentioned in our 5.3 Silverado reviews guidelines. If not, then there can be the opposite of what you would have expected.
Source: CNC machined flanges and thick flanges -https://forgedcomponents.com/cnc-machine-types-high-flange/