Headers for BluePrint Engines
Over the last decade, BluePrint Engines has captured a significant market share of crate engine sales for small-block Chevy, big-block Chevy, and small-block Ford engines, and has recently started offering GM LS and a few Chrysler engines. How can a relatively straightforward crate engine cause so many problems finding the correct header set? Depending on someone’s interpretations of the concerns, they can be identified as either minor or more problematic and costly.
As BluePrint Engines’ popularity has surged, so has the number of problems and requests for compatible headers. We are contacted every day by persons who have already ordered or received a BluePrint engine and are searching for compatible headers. Others will contact us because they are considering a BluePrint engine but have heard of or read stories on various web forums regarding difficulties in finding compatible headers.
Researching compatible headers can be daunting. Larger manufacturers, now often controlled by private equity investment firms, are known to care little for the end customers, dealer networks, or providing the necessary information a potential buyer needs. Adding to the complexity is when the staff at BluePrint do not understand the requirements. Although BluePrint instructs its customers to contact a few header manufacturers, they do not adequately explain why.
Only a few header manufacturers are on BluePrint Engines’ recommendation list. The sales staff for one of those companies (which is no longer on their list) would often tell its customers that they do not offer anything for these engines. One is a custom header manufacturer, with a starting cost for their products of $2,000.00 per set. Sanderson Street Rod Headers is also one of the recommended companies. However, with any of these recommendations, the BluePrint staff does not offer clear or accurate information that describes why header selection for their engines is complex or troublesome. This article provides the necessary information, explanations, and guidance to find the proper header for your application.
Contact us. We can help with new headers for your application or explain the steps necessary to achieve compatibility!
This statement is not entirely accurate. Although the manufacturing jigs for a small number of small-block Chevy header sets have been tweaked to provide additional application compatibility, including BluePrint, Sanderson typically applies dimples to the primary tubes in the locations necessary for spark plug clearance.
For example, part number CC158BP is identical to CC158, but features dimpling on the four center tubes for improved spark plug clearance.
When an order is placed for Sanderson Headers and it is specified that they are intended for a Blueprint or other Vortec-based cylinder heads, a note is added to the order. This ensures the header set is compatible with the application, and Sanderson will perform any necessary dimpling for spark plug clearance before shipping it to the customer.
Yes and No.
- They are not specifically unique. The cylinder head design for BluePrint small block Chevy applications is based on the GM Vortec regarding spark plug location.
- When BluePrint started using their own small-block Chevy engine block castings, that created a few problems. At first glance, these engine blocks resemble the GM Target Motor replacement crate engines of the mid-to-late 1980s. However, the BluePrint castings are slightly wider in some areas than standard GM castings, for example, the raised area around the expansion plugs. This has created clearance issues with some tight-fitting block hugger headers.
- BluePrint cylinder heads for small-block Chevy, big-block Chevy, and some small-block Ford engines utilize a raised port design. This identifies an exit location of nearly 1/2" (12.7 mm) higher than original cylinder head designs.
BluePrint customers often focus too much on the raised port. It simply means that the header mounts higher up the cylinder head, although it can affect header compatibility. Understanding how this is a concern is described in the following item.
Yes and no. It depends on the header design, which is often specific to the vehicle for which the header is intended.
This is addressed in more detail within the main article content. For small-block Chevy applications, spark plug location is the primary issue. However, on the other engines, the raised port may cause spark plug clearance problems or chassis clearance issues with specific header designs.
Header designs that have a primary tube that runs parallel to the cylinder head and under the spark plugs can experience reduced or net-zero clearance if the header mounting moves up ~1/2" (12.7 mm). We see this when the forward tube on the header routes under the first or first two spark plugs.
Chassis and component clearance issues may occur if the space above the header tube routing is already limited. The dimension associated with the amount a port is raised is the same value of clearance reduction. If the exhaust port exit is raised 1/2" (12.7 mm), the available clearance above the header tubes is reduced by the same amount.
Although there are some header part numbers with "BP" in the SKU for BluePrint applications, this is mostly for resellers who require a unique SKU for each product.
For example, part number CC158BP is simply the CC158 header set with dimpling applied to the four center tubes for spark plug clearances.
The inclusion of "BP" in the SKU helps Sanderson in other ways. The manufacturing jigs for a few of their header sets have been recently modified slightly to allow additional application compatibility. Having 'BP' in the part number indicates that the manufacture date occurred after 02/2025.
The slight tweaking of the jig does not affect the original design or vehicle compatibility. For example, the Sanderson CC16 is one such header. Part number CC16 remains as the foundational part number. Previously, the CC16 was dimpled for BluePrint applications in multiple locations and identified on the customer's invoice with a note. The CC16BP has fewer dimple locations and helps Sanderson identify this header set in the future as one built on the latest jig configuration.
Short answer, maybe. For example, many small block Chevy header sets do not include "BP" in the Sanderson part number but are already compatible with BluePrint engines by default. Other part numbers are documented for BluePrint on the paperwork and do not include 'BP' in the part number, at least for now.
For other engine applications, including big block Chevy, Ford small block, GM LS, and the small block Chrysler, these engines experience fewer spark plug clearance issues than the small block Chevy. On these engines, the raised port is the primary difference, and headers tend to be either compatible or incompatible with these engines. There are often fewer compatibility issues with BluePrint engines; however, there are also fewer basic solutions when clearance issues arise.
The answer is yes, but it is complicated.
Many of these companies are too big to care. They do not have an interest in caring about compatibility or even taking the time to check. Larger companies will often ignore these requests by simply offering a blanket 'no' statement, stating that they do not offer any products for the BluePrint engines. It only means that they haven't checked and do not care to make any effort to do so.
This leaves compatibility verification to the purchaser, installer, or smaller resellers who take the time to help identify and share information on these products. We can help!
We have identified numerous header offerings from Doug's, JBA, Hedman, and other manufacturers, which are compatible with BluePrint. Although many of these header sets install without any clearance issues, some may require a minor modification.
This question can create problems, but it also presents an opportunity to educate our customers.
Please do not install an oxygen sensor bung in your headers. The preferred location for the oxygen sensor is in the downpipe, approximately 8" (20 cm) to 14" (36 cm) after the header collector.
There is one exception to the above recommendation. An oxygen sensor can be installed in the header on applications using a full-length header set that features a long collector with at least 10" (25 cm) of collector tubing length after the oxygen sensor bung location. The 10" (25 cm) is barely enough to provide a clean reading on 'some' applications. However, it is recommended to have at least 12" (30.5 cm) for more accurate readings, and better yet, if the application has a few feet of exhaust piping after the oxygen sensor.
Negative Effects:
Having the oxygen sensor in the header restricts air flow and increases turbulence. This steals power and torque. The location can also affect the measurement accuracy.
The measurement is not considered 'clean' if outside reversion air enters the exhaust piping, causing the sensor to register cleaner air, now reported to the computer as a lean condition. The inaccurate measurement value is transmitted to the computer, which will respond by increasing the fuel volume. The erroneous measurement and reporting create an overly rich fuel mixture, which the sensor now reports as stoichiometric (having a correct air-fuel ratio), even though this claim is quite inaccurate.
GIGO, or "garbage in, garbage out. This is commonly associated with computer science and software programming. If the oxygen sensor measures contaminated exhaust gases (an odd term, implying that exhaust gases are contaminated by fresh air), it will provide incorrect information to the computer, and the computer's response will also be inaccurate.
The inaccurate response from the computer can create new problems.
- The broadest example is a substantial change in exhaust gas temperatures (EGTs). If an engine is too lean or too rich, the EGTs may skyrocket. High EGTs can exceed the capabilities of header coatings and finishes, leading to failure.
- An overly rich condition can contaminate the engine's oil supply, leading to engine damage or failure.
- The accumulation of additional carbon on the piston tops and valves can cause further issues.
The BluePrint and Sanderson Headers Back Story:
A few years ago, my good friend Donna Smith, the owner of Sanderson Headers, called to ask if I knew anything about the BluePrint engines, specifically their cylinder heads. She explained that they were experiencing a considerable number of header returns, with customers complaining of various clearance issues on small-block Chevy applications.
To be transparent, I created and manage the Sanderson Headers website, answer their online and social media tech support questions, and wrote their Header Tech 101 booklet.
I explained the spark plug locations and raised port design to her, and she exclaimed that they did not have any components from BluePrint that would allow them to test compatibility. She would have to stop selling headers to anyone with a BluePrint engine until they could verify compatibility. I suggested contacting BluePrint, but she responded that she was busy at the moment and didn’t have time. So, I offered to call the company for her, and she agreed.
I called BluePrint and spoke with who I believe was their national sales manager. I explained who I was and for whom I was calling, explaining the problem and what was needed. I asked if BluePrint had any damaged, warranted, broken, or otherwise unusable empty (no parts) small-block Chevy cylinder heads that Sanderson could use at their factory to place on one of their empty engine blocks to verify header compatibility. Would they sell an empty, no parts, cylinder head? No! He repeated no, multiple times throughout the brief conversation. They did not have any warranted, broken, blemished, or unsalvageable cylinder heads. I was very clear about the request, but his response was a firm ‘no.’
I immediately called Donna to inform her of the conversation and let her know that BluePrint offered no assistance. Still, I had a few other ideas to locate the components she needed. About 30 minutes later, she called me back. “BluePrint just called,” she began, “asking if I knew a Sam from Century Performance who was trying to get a free pair of cylinder heads and have them sent to Sanderson Headers.” She then repeated everything I had already discussed with him. No, it wasn’t for me. No, I wasn’t looking for free components, etc. She reiterated the problem to him and explained why Sanderson needed a cylinder head to verify compatibility. He immediately agreed to send over anything she needed, both then and in the future.
To reiterate, BluePrint is sharing some inaccurate or incomplete information regarding the reasons for header incompatibility and how various header companies are addressing fitment issues.
The knowledge offered in this article will benefit both our current and future customers.
Header Issues on BluePrint, SB Chevy Compatible Engines, Explained
The BluePrint small-block Chevy compatible crate engines tend to generate the most fitment problems. What are the concerns regarding the BluePrint engines and other engines using Vortec-based cylinder heads? The answers are provided below. A considerable amount of information is intentionally provided to ensure a comprehensive understanding of the issues and the proposed solutions. Please don’t hesitate to contact us if anything provided here is unclear or if your application has any additional or unique issues.
- The term Vortec-based in this article refers to the spark plug location. Vortec-based cylinder heads, including BluePrint, move the spark plug further from the center of the combustion chamber and closer to the exhaust valve. This brings the two center spark plugs ~1/2″ (12.7 mm) closer together.
- Header designs with a tight tube radius near the cylinder head may require dimpling1 of the tubes for spark plug boot clearance. This often depends on the tube size, but the header design may mandate dimpling1 regardless of the tube size. Some large tube headers cannot be dimpled1 because the amount or depth required to create enough clearance is more than reasonably necessary to maintain the internal dimensions of the tubing. A different header design would be necessary.
- Header designs with tube routing not meant to accommodate this spark plug location may require dimpling1 for spark plug boot clearance.
- Dimpling1 of the header primary tubes may not be the best solution for some header designs if this modification creates other problems.
- Not all Vortec-based cylinder heads will have 4.0″ spark plug spacing on the two center plugs. This dimension varies on many aftermarket Vortec-based heads. If the dimension is less than 4.5″, it is still recommended to consider it a Vortec-based head.
- BluePrint small-block Chevy compatible cylinder heads utilize a raised port design. This means that the exhaust ports AND the header mounting location move up on the cylinder head ~1/2″ (12.7 mm).
- Any header design that includes a tube that runs parallel to the cylinder and under the spark plugs may encounter spark plug clearance issues if the distance between the tube(s) and the spark plug(s) is already minimal. Dimpling1 of the tube for clearance may be required.
- Raising the header mounting up ~1/2″ (12.7 mm) may cause clearance problems with the vehicle chassis or other components in the engine bay. Fitment testing is a crucial step in the installation process.
- Examples can include a full-length header with a collector that is already close to the underside of the body or floorpan. Or, a vehicle with a manual transmission and factory Z-bar (mechanical clutch linkage). Moving the header up 1/2″ (12.7 mm) may create interference issues with the clutch linkage.
- NOTE: Most Vortec-based aftermarket cylinder heads do not include a raised port design. However, the mounting location is something to consider. Use the image graphic below to identify the measurement location that helps determine the proper location for required dimpling1.
1 Dimpling: The act of producing a depression or indentation in the surface of (something).
All Other BluePrint Engines
BluePrint offers additional crate engines for popular, compatible V8 applications. These include:
- Big Block Chevy
- GM LS
- GM Marine (small and big block Chevrolet)
- Small Block Ford (302 and 351W based)
- Chrysler Small Block
- Chrysler 426 Hemi
Notes: The small-block Chevy compatible marine engines meet the same requirements as the non-marine engines. The two Chrysler-compatible engine offerings utilize standard exhaust port locations and sizing. The small-block Ford engines feature raised exhaust ports in some configurations. Please identify which cylinder heads are used on the engine ordered. The Big-block Chevy-compatible engines utilize a raised exhaust port location. BluePrint uses GM LS3-based cylinder heads for the LS-compatible engines. The BluePrint LS cylinder heads differ slightly on the exhaust side from those of a common LS3, but not enough to affect header selection.
The Raised Port Exit
Many do not understand the definition of raised port. It identifies a port exit location that is higher up the exhaust face of the cylinder head. If the raised amount is 0.200″ (1/5″), 0.500″ (1/2″), or whatever the value provided by the manufacturer, the header mounting is merely that much higher than a standard mounting location. The port opening and the mounting hole locations move up the exhaust face of the cylinder head by that amount.
The raised port exit can cause clearance issues between the spark plugs and/or the chassis on some header designs. This is a deliberately vague statement. The infinite number of engine, header, and vehicle combinations makes it impossible to state anything more specific. One combination may experience zero issues, where everything fits perfectly as if it were planned. On others, everything could go sideways, where the only option is an expensive, custom-built header set.
Consider an already tight-fitting header with a cluster of tubes in its design. Moving the mounting up the ~0.500″ on the BluePrint heads reidentifies a perfect-fitting header for standard cylinder heads now incompatible with BluePrint. A few examples include the Sanderson BB3 for big-block Chevy A-body applications, and the Sanderson FF4 and FF5 header sets for small-block Ford engines in a wide range of classics and street rods.
Small Block Ford 2.0″ vs 3.0″ Header Flange Bolt Spacing
The mounting flange bolt spacing on small-block Ford engines is an issue not limited to BluePrint engines. The 3.0″ spacing has shown up on a variety of aftermarket cylinder heads for the sole purpose of allowing larger header primary tube diameters. However, there are a few caveats to be aware of.
Most thick flange header designs are incompatible with the 3.0″ bolt spacing. The thicker flange extends over the spark plug opening, making installation and removal of the spark plugs nearly impossible. This forces the use of thinner flange header designs or extensive modifications to thicker flange headers. The changes often reduce the material around the mounting holes, which may create additional problems.
If the engine mandates the use of a 1-3/4″ or larger primary tube header, the 3.0″ spacing is often mandatory. It is helpful to be aware of these special considerations to avoid any surprises if modifications are required. Here is an example of a 3/8″ thick header flange and a popular 3.0″ spacing cylinder head, and how it affects spark plug access.
Do We Offer BluePrint-Compatible Headers?
Yes, we offer a variety of compatible header sets from various header manufacturers for the BluePrint engines. We have verified many header part numbers from various header manufacturers that fit on BluePrint engines. Sanderson Headers is one such company. However, Sanderson does not have headers for every possible engine and vehicle combination, and their product focus revolves around street rods, classics, and some engine swaps. High-performance and racing applications require header sizes and designs outside of what Sanderson offers.
Other header manufacturers offer compatible header sets, but do not advertise them accordingly. They either do not know (or care to know), have not received enough customer feedback, or wish to avoid any possible fitment support headaches related to the BluePrint engines. That is why many header companies say ‘no’ to questions of BluePrint-compatible header availability.
We have been compiling a list of header sets from various manufacturers that our customers have found to be compatible with BluePrint engines. Many require zero modifications and fit as if the decades-old design was initially intended for these engines. This list continues to grow as we identify and verify new products. Some headers may require minor adjustments to achieve a proper fit. The term ‘minor’ is important! If a header set requires anything beyond a minor tweak, it is deemed incompatible.
On applications where we are unsure of proper compatibility, we advise the customer on the methods to test-fit the header. We can then help to determine whether minor modifications are acceptable and instruct the customer on safe techniques, or suggest returning the product.
NOTE: Once a header set has undergone any modification attempts, it becomes non-returnable and often voids the manufacturer’s warranty. This is why we are explicitly clear in the conversations with our customers about what is required and the consequences. The customer assumes all liability. However, we will strongly advise against any modifications that go beyond minor changes. We want to solve problems, not generate more!
Is it possible to modify a ceramic-coated header for clearance?
Absolutely, and without damaging the coating! There are specific steps that must be taken, but again, recognize the consequences described above. If a header requires a level of modification that could damage the coating, we advise the customer against it. For example, basic dimpling for clearance can be achieved without damaging the coating when executed properly.
If extreme modifications are necessary, it is advisable to purchase a used or plain (sometimes temporarily painted) header set to modify. Once finished, the header can be sent out for application of a ceramic coating or other customer-chosen finish.
The final option is a custom header set. These will be specific for the engine and vehicle application. The primary downside is the financial impact. Custom header sets are expensive. The base starting price typically ranges from $2,000.00 to $3,000.00 for the set, and often increases depending on the needs or uniqueness of the application.
In Closing
Finding a header set that is compatible with a Blueprint engine can be daunting. Many header manufacturers say ‘no’ when potential customers ask if they have a header set for a BluePrint engine, even before the customer provides details on the vehicle application. In my opinion, this is nothing less than laziness.
We understand the necessary specifications a header set must have to be compatible with the BluePrint engines. The misunderstanding of spark plug location, raised port, and other factors is troublesome for many BluePrint customers.
From this article, the reader should be able to determine that I regularly assist Sanderson Header customers with their questions on header compatibility and BluePrint engines. The association I have with Sanderson goes beyond the creation, updating, and hosting of their website. I also respond to Sanderson customers use create support desk tickets on their website. Additionally, when someone calls Sanderson and reaches their voicemail, the message advises the caller to contact ‘Sam’ for tech and application assistance. I am the Sam that the message references. Donna, the owner of Sanderson Headers, will often refer to me as their ‘senior tech’ or something similar, on the message. This shows her sense of humor.
Although I assist dozens of potential Sanderson Header customers every day, the company I founded over 35 years ago, Century Performance Center, Inc., is also a reseller of Sanderson products. However, we also offer many other header brands to our customers, including Doug’s, JBA, BBK, Banks Power, Schoenfeld, Hedman, and Gibson.
Offering multiple header brands has allowed us, with our customers’ patience and assistance, to identify a variety of headers that are compatible with BluePrint engine applications.
The BluePrint engines are popular because they offer customers a great product value. Their engines are manufactured and assembled using modern machining techniques and quality components. Offering engines that have been tested, checked on a dyno, and include what is possibly the best warranty in the industry continues to drive sales today, and well into the future.
Sales and Support Phone (775) 746-4887
Call today! Our staff will help you find the correct header set for your application. In addition, we also offer BluePrint engines. Call to check availability.
