Ultimate LS Cathedral Port Cylinder Heads Guide (2023)

Cathedral port cylinder heads have been mistakenly dismissed by many in LS-series circles for being “old-tech.” However, their thin cross-section allows for a high-velocity and smaller-volume runner design with excellent flow. For a street car, this design means excellent throttle response, torque and average power.

Dyno tests have proven that comparable aftermarket cathedral port heads can match a rectangular port in peak power, while proving much more impressive below the curve. For road racing, a cathedral port is ideal, and has even proven to be quite capable in drag racing with an altered valve angle and larger runner sizes.

This Tech Tip is From the Full Book,HIGH-PERFORMANCE GM LS-SERIES CYLINDER HEAD GUIDE. For a comprehensive guide on this entire subject you can visit this link:

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Factory Heads

LS1

The OEM design that started it all, the original Gen III cylinder head, helped produce 350 hp using 5.7 liters of displacement. There are changes throughout the model years, which are indicated with various casting numbers (last three digits are the part number). The later “241” castings featured lighter valves, a more common center valve cover bolt configuration, and several other nuances that make them more desirable than the “853” casting. Though no longer produced by GM, all versions are fairly abundant used and work with any factory (or larger) bore. If you are new to Gen IIIs, please note that these heads are aluminum and unless otherwise noted, so is every other head in this book.

LR4/LM4/LM7

Following directly in the engineering footprint of the LS1 casting, these cylinder heads were used on the 4.8- and 5.3-liter truck engines. The only differences between these heads and the LS1, besides the price, are the valve size and combustion chamber. Out of the box, the small valves make these heads a poor choice for performance applications, but these components are easily upgradable, which often makes for a great high-compression head that is easy on the wallet. These heads have been phased out of production in favor of higher-flowing, LS6-based castings. However, they are quite plentiful used and work with any bore size; search for casting numbers “852” and “706.”

LQ4

These heads came on low-performance 6.0-liter truck engines in two variations: “873” cast iron (1999–2000) and “317” aluminum (2001+). The early design was the only castiron LS head ever made, and the least desirable in a performance application. However, the later heads can be a good choice for boosted applications because they offer larger runners and combustion chambers (for lower compression) over the factory LS1 heads. Because these heads are no longer in production, they must be purchased used. Though they are not the most common, they are also not the most desirable, so the price tag is usually very reasonable and work with any bore size.

LQ9

The hipo 6.0-liter truck engines, such as the Cadillac Escalade, received this variation on the LS6 head. Though the runners are identical to those on the LS6, its combustion chambers are larger, just like the LQ4. This combination of optimal runner design and larger chambers makes the “035” head (aka “317”) the best of the OEMs for boost. These heads are no longer in production, replaced on 6.0- and 6.2-liter truck engines with the L92 head, but used castings are not uncommon or unreasonably expensive. Because of the small valves, these heads fit on small-bore applications (though the large chambers may be a bit much).

LS6/LS2

In its most potent form, these heads supported a conservatively rated 405 hp on the Z06 Corvette. The LS6 was designed specifically by GM to surpass the LS1 as the best performance head, and it did such a good job that the “243” casting was recycled on the LS2. Aside from the LQ9, which is a copy of the LS6, these are the best performing of the OEM cathedral ports. Though the LS6 and LS2 are no longer in production, brand-new bare castings are still available for around $850 from Chevrolet Performance Parts dealers. In production these heads have been repurposed on the aluminum 5.3L truck engine (L33, “799” casting), which proves that despite being originally made for a 3.90-inch bore, these heads even fit on 4.8/5.3L blocks (3.78-inch bore), and are quite abundant used.

Aftermarket Heads

Although Chevrolet has invested plenty of time and effort into engineering a fine array of cylinder heads for the LS-Series engines, it still must focus on the needs of the mass-market consumer. Aftermarket companies have no such restrictions, and can craft performance-specific castings to meet the needs of racers and hardcore enthusiasts. Some of them are custom porting jobs based on existing factory castings, while others are completely custom castings.

This means an incredibly broad range of port sizes, chamber depths, and valve options exist for the discerning LS head shopper. Whether you’re designing an engine from the ground up or updating an existing powerplant, the odds are strong you’ll be able to find a head that suits your needs whether you’re drag racing, road racing, or off-roading. If you need to feed a big-inch stroker LS or are adding forced induction, a well-engineered head that can aid your quest for power almost certainly exists.

On the following pages you’ll find the pertinent information and dimensions for just about every commercially-available aftermarket cylinder head. Please note that the flow numbers have been provided by the manufacturers, and may not be perfectly comparable because they were acquired on different equipment. Still, they should be close enough to serve your needs when looking for a particular flow range.

Advanced Induction

Includes:

GM 706/862

5.3-Liter LS1, 218 cc

GM 243 (LS6) and 799 (LS2), 218 cc

GM 243 (LS6) and 799 (LS2), 226 cc

While not the largest name in the industry, AI is well respected. This North Carolina–based shop is practically a factory for CNC head porting, with programs for the Gen II, III, and IV small-block only. Specializing in such a finite area makes AI particularly knowledgable, precise, and efficient. Each program is well thought out to appeal to a particular and common customer need. At the time of publication, AI had just completed several new heads with aftermarket and factory castings. It also offers intake manifold porting and valvetrain kits with a specially designed camshaft.

Advanced Induction

GM 706/862 5.3-Liter LS1, 218 cc

Advanced Induction (AI) takes the GM “706” casting to the next level by replacing the small factory valves with Manley Racemaster stainless-steel valves, suitable for a 3.90-inch bore. These heads boast plenty of piston-to-valve clearance for an 11:1, stock cubic-inch LS1 with a large-duration cam (without cutting piston reliefs), though cutting the chambers can easily put compression over 12:1. AI claims this reasonably priced offering is easily capable of 440 to 480 rear wheel horsepower (rwhp) with one of its cams and supporting bolt-ons in a 346-ci engine. A similar program for the “241” casting is also available. The machining and labor costs alone are $1,145 (there is a separate cost for various valves and valvesprings and other options). The buyer must supply a core. Because stock valves are used, there is no limitation on bore size.

Advanced Induction

GM 243 (LS6) and 799 (LS2), 218 cc

The 218-cc LS6/LS2 head is a mild upgrade from the basic performance rebuild, which boosts flow by 32.2 cfm on the intake side and 28.5 cfm on the exhaust side, at .600-inch lift, despite the more cost-conscious machine work. That is not to say, of course, that the 218s don’t go through the same rigorous and thorough machine work as AI’s other heads: CNC-ported runners, PCD-milled deck, flanges, and valve cover rail. AI claims these heads are worth 20 to 30 rwhp over the stock, as-cast heads. The base machining and labor cost is $795, plus a $775 core charge (for brand-new heads). Additional charges apply for various components and options. The stock valves allow for any bore size.

Advanced Induction

GM 243 (LS6) and 799 (LS2), 226 cc

AI’s flagship cathedral port increases the port volume by 15 cc over stock, allowing up to a 41-cfm improvement over stock while still utilizing the factory GM valves (reground). Despite the larger runners, AI claims these heads produce great power under the curve, crisp throttle response, and no loss in driveability. Although the stock valves would seem to hold them back, many records are owed to these heads from stock cubic-inchers to strokers, especially on heavier vehicles such as GTOs and Trailblazer SSs. A special high-compression version is also available to allow plenty of piston-to-valve clearance for big cams with a smaller chamber and stock pistons. Machining and labor runs $995, plus a $775 core charge (for new heads); however, additional charges apply for various components and options. There is no bore size limitation.

AirFlow Research

Includes:

LS1, 210 cc

LS1, 215 cc

LS1, 230 cc

LS1, 245 cc

AFR is a staple in the aftermarket cylinder head market, beginning in the 1970s and pioneering CNC porting with its revolutionary tapefed CNC machine. NHRA legends Bill “Grumpy” Jenkins and Warren Johnson both got their power from AFR aluminum heads. In the 1980s AFR loaned its services to GM and NASCAR, pioneering the use of wet flow technology. In the early 1990s the company began full production, and incorporated advanced, high-density cast-billet technology. At long last this brought full five-axis CNC-ported aluminum heads to racers at an affordable price. AFR became the first to offer aftermarket LT1/LT4 heads, the first to receive a CARB EO number, and the first to introduce an LS1/LS6 head. This family-owned and operated organization is based in southern California, and continues to stay on the cutting edge. (Photos Courtesy AirFlow Research)

AirFlow Research

LS1, 210 cc

The small-port, high-velocity, 210-cc Mongoose is an update of the head that started it all. While others were still developing CNC programs for OEM castings, AirFlow Research (AFR) started with a clean sheet of paper and used the CNC machine to further manipulate its well-formed design. The latest iteration boasts excellent torque for smaller-cube combos, and many added features to benefit forced induction and overall durability while still compatible with factory rocker arms, intake manifold, etc. Later, center-bolt-style valve covers are required, as with all AFR castings. These heads are built for a 3.900-inch bore or larger and cost $2,400.

AirFlow Research

LS1, 215 cc

The 215-cc Mongoose was designed specifically to maximize the 4-inch bore, and is an excellent choice for street-based applications. However, the 215-cc head can also be a good choice for aggressive or forced-induction 346-ci combinations. This fully CNC’d aftermarket casting also boasts high velocity and is still compatible with all factory equipment. Though it was designed for a 4-inch-or-larger bore, this head is also compatible with a 3.90-inch bore and simply bolts right on with factory components and fasteners. Fully assembled, the 215s go for $2,465.

AirFlow Research

LS1, 230 cc

Available in small- and large-bore variations, the 230-cc Mongoose is extremely versatile and perhaps the most capable emissions-legal head on the market. For an all-out, boosted 346-ci combo this head gives up some low-end torque, but screams up top. However, it is ideal for naturally aspirated strokers (396 to 427 ci). Plenty of added features make this a competitive head for the money, especially since it is compatible with all factory equipment. The minimum bore size required is 3.90 inches, with three different chambers available; the largest of which is intended for larger bores (such as 4.060 to 4.125 inches). Total cost, fully assembled, is just under $2,600.

AirFlow Research

LS1, 245 cc

The large-bore 245 cc is AFR’s flagship, maximum-effort head. Machined to accept .375-inch pushrods and equipped with 1.570-inch spring pockets, this head is indeed solid roller friendly. With high-end flow reaching 360 cfm at .650-inch lift, the 245 cc is comparable to an LS7, but with greater exhaust flow. This combination enables more than 700 hp while still providing gobs of low- and mid-range torque. Like the rest of the line-up, this head still uses stock valve lengths and geometry, and is compatible with factory equipment. A 4.200-inch-bore head gasket is required; meanwhile, the heads can actually be used on a 4.00-inch-bore block (or larger). However, only the most aggressive, race-only 4.00-inch-bore combinations require such a stout head. Expect to pay $2,700 for a fully assembled set.

This Tech Tip is From the Full Book,HIGH-PERFORMANCE GM LS-SERIES CYLINDER HEAD GUIDE. For a comprehensive guide on this entire subject you can visit this link:

LEARN MORE ABOUT THIS BOOK HERE

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Edelbrock/Lingenfelter

Includes:

LS1 Performer RPM, CNC

LS1/LS2, E-CNC 215

One of the oldest names in the industry is Edelbrock. Vic Edelbrock, Sr., designed and sold his first intake manifold in the late 1930s (for the Ford flathead). It wasn’t until 1946, however, that the first catalog was printed as the business was temporarily put on hold for World War II. In 1948, Vic Sr. purchased one of the industry’s first engine dynamometers, which lead the way for revolutionary small-block Chevy intake manifold designs. In 1962 the company was handed to Vic Jr., following the passing of his father, who has continued the tradition of building well-tested, quality parts in Southern California. Edelbrock has its own aluminum foundries with a permanent-mold and heat-treat facility located nearby, for a 100-percent Made in the USA product. Edelbrock continues to use its resources as the basis for some incredible products from budget to high-end and street to full-on race. (Photos Courtesy Edelbrock)

Edelbrock/Lingenfelter

LS1 Performer RPM, CNC

Edelbrock worked with Lingenfelter Performance to use its aftermarket casting to create an allout, high-flowing street/strip head. These heads come in a smaller 203-cc intake runner and a 230-cc runner for strokers. The smaller version is perfect for stock cubic-inch combos, and flows plenty of air. Plenty of other great features are afforded by the clean-sheet casting design, though these heads are compatible with factory rockers and other components. These heads bolt right on to any 3.90-inch-or-larger bore and come fully assembled for $1,350.

Edelbrock

LS1/LS2, E-CNC 215

These 50-state-legal heads are fully CNC-ported, and a nice upgrade over stock LS1, LS6, or LS2 heads. The cost is kept down, but the quality is kept up. These heads are a great choice for a stock-cube build, yet provide plenty of room to grow–giving plenty of material for further porting. The larger-than-stock sized valves are said to pose no clearance issues for even the 3.7-inch bore size. All factory equipment bolts right up including the later, center-bolt, style valve covers with factory or aftermarket fasteners. Retail price is only $1,045.

Livernois Motorsports

Includes:

LS2 Stage 2, CNC

LS2 Stage 3, CNC

Livernois has its roots in engineering, starting in 1949, becoming the first to produce aluminum radiators for automotive use as well as the tooling and machines to produce them. Over the years, the Michigan-based firm’s location has enhanced its use to OEMs as well as local hot rodders. Today the same philosophy of rigorous testing and design has helped the company design many CNC programs for OEM and aftermarket castings. In the LS community, Livernois is most famous for its fifth-generation Camaro products and services, and managed to lay claim to the very first 2012 Camaro ZL1 to run a 9-second quarter-mile using a Livernois cam and CNC-ported heads. (Photos Courtesy Livernois Motorsports)

Livernois Motorsports

LS2 Stage 2, CNC

Known for its high-horsepower, boosted combinations, Livernois has several great CNC-ported stock castings starting with the LS2 Stage 2. Using a 5-axis CNC machine, the Stage 2 boasts many high-quality parts proprietary to Livernois, such as a dual-valvespring package with titanium retainers and Viton seals. The only difference between the Stage 2 and the Stage 3 is the valves, the lesser version uses new GM valves, though it does have a CNC valve job to smoothly transition into the chamber. The stock valves allow these heads to fit on the small-bore 4.8/5.7-liter blocks, and are otherwise compatible with all factory equipment. The $1,400 price tag includes the cost of the core, all components, and assembly.

Livernois Motorsports LS2 Stage 3, CNC

Livernois’ 5-axis CNC machine carves up the Stage 3 heads to the tune of 310.9 cfm at .600-inch lift, which definitely takes advantage of the larger stainless valves in the higher lift range. Supercharged and nitrous applications definitely take advantage of the high-flowing exhaust port. The valve choice makes this head appropriate on a stock 3.90- or 4.00-inch bore. These added components bring the price up to $1,800, which includes the core and assembly, so they are ready to bolt up right out of the box with no other fees or charges.

Mast Motorsports

Includes:

LS1/LS6, 11-Degree Small-Bore

11-Degree 6-Bolt Small-Bore

12-Degree 6-Bolt Large-Bore

Mast is one of the newest, brightest, and fastest-growing developers of LS parts. The Texas-based company was founded on the principles of engineering, developing high-quality LS components, and thorough assembly of LS crate engines—embracing new and cutting-edge technology. In addition to the engineering talents of its owner Horace Mast, it also employs Cary Chouinard, the brains behind ET Performance and Performance Inductions¬ (the first companies to develop aftermarket castings with altered valve angles). Mast is constantly developing new products for the LS market that push the design envelope for the highest performance, such as its splayed-valve designs and the canted-valve Mozez head. (Photos Courtesy Mast Motor-sports)

Mast Motorsports

LS1/LS6, 11-Degree Small-Bore

Similar to the ET Performance 11-degree castings of years past, which were a big game-changer, these heads are ideal in a smaller cubic-inch combination with a big lift, high-duration cam (thanks to its flatter valve angle). The flow capabilities are unmatched at this runner size, which means torque does not suffer when bolting on Mast’s fresh casting. Unlike its predecessor, the Mast 11-degree head uses any LS3-style rocker arms rather than a special set of shaft-mount rockers. Save up your pennies because these fresh castings command $1,299 each.

Mast Motorsports

11-Degree 6-Bolt Small-Bore

The 6-head-bolt provision makes this high-flowing head ideal for cubic-inch limited aftermarket block combos, or those with LS2- or LQ9-based engines who are looking to upgrade to an aftermarket block later. The runner size makes it appropriate for high-boost, smaller-cube combos, or larger-cube naturally aspirateds, with a 3.90-inch or larger bore. Medium (4.00 inch or larger) and large (4.125 inches) bore versions are also available. The added head bolts add another $200 to the price ($1,499 total), but these are also compatible with any LS3 rocker arms.

Mast Motorsports

12-Degree 6-Bolt Large-Bore

The flagship of Mast’s cathedral port designs boasts excellent flow all the way to .750 inch of lift. Though cathedral ports are usually not the preferred choice for large-cubic-inch builds, these heads could change all that. Hitting 373 cfm at .750 inch of lift, these heads are on par with many good rectangular ports while boasting much better velocity and exhaust flow. With massive valves for a cathedral, it is no surprise that these heads use LS7-style rocker arms and are appropriate for a 4.125-inch- or-larger bore. Retail price is $1,599 each (at time of this article).

Patriot Performance

Includes:

LS6/LS2 & LQ9, Stage II

LS6/LS2 & LQ9, Stage III

LS1, Stage II, 5.3-Liter

Patriot is known for producing a high-quality product at an affordable price, among several different platforms. Maximum air and fuel flow are achieved by in-house CNC designs altering the chamber, bowl, and runners. While it started with CNC programs for OEM casting heads, Patriot has branched out into clean-sheet designs while still at an affordable price. The Alabama shop recently opened a new facility to better serve its customers.

Patriot Performance LS6/LS2 and LQ9, Stage II

At a very reasonable price, the Stage II CNC porting increases flow by 65 cfm on OEM castings. The LS6/LS2 casting is best suited for higher-compression, naturally aspirated engines and 75- to 150-hp shots of nitrous. The larger chambers on the LQ9 casting make it better suited for mild-boost applications. Both are available with 2.02- or 2.055-inch intake valves and are machined on a 5-axis CNC. Fully assembled, these heads sell for a wallet-friendly $1,335 (at time of article) and are compatible with all factory parts and a 3.90-inch bore.

Patriot Performance

LS6/LS2 and LQ9, Stage III

The Stage III is also a reasonably priced CNC-ported OEM casting, which boosts flow by 80 cfm. The LS6/LS2 casting is best suited for higher-compression, naturally aspirated or nitrous engines. And again the larger chambers on the LQ9 casting make it better for boost. Both are machined on a 5-axis CNC, and ideal for a 4-inch bore given the large valves and chambers (but do fit a 3.90-inch bore). Thankfully, the added flow does not come at a premium, and the Stage III costs the same $1,335 (at time of article) as the Stage II.

Patriot Performance

LS1, Stage II, 5.3-Liter

The most economical of the bunch, CNC programs for either the 5.3-liter truck casting or perimeter bolt 1997–1998 LS1 castings offer a 60-cfm jump in flow over stock. The LS1 casting saves the expense of converting the valve covers, coil brackets, and other associated parts. The only catch is the larger 67-cc combustion chamber, as opposed to the 5.3’s smaller chamber, which can bump compression to 10.8:1 on a stock bottom-end LS1. Both are machined on a 5-axis CNC, work well in naturally aspirated engines, and with a 75- to 150-hp shot of nitrous. The smaller valves and chamber make these heads compatible with most any bore, and cost a mere $1,230 (at time of article) ($1,095 for early LS1 castings).

Precision Race Components

Includes:

Stage 2.5, 5.3-Liter

LS6 Stage 1, 6.0-Liter

LS6 Stage 2.5, 6.0-Liter

LS6 Stage 3, 6.0-Liter

215 cc

227 cc

237 cc

PRC is the R&D and production arm of Texas Speed, developing cylinder head programs for the LS market, including its own aftermarket casting. PRC is known for extensive flow and dyno testing of all its heads as well as affordability. In terms of quality and performance per dollar, PRC is hard to beat. It is no wonder PRC cylinder heads have a few long-standing records in the LS drag race community. (Photos Courtesy Precision Race Components)

Precision Race Components

Stage 2.5, 5.3-Liter

Don’t be fooled by the price tag, these cylinder heads have excellent capabilities, which have been exploited on many potent head/cam combos. New “862” or “706” casting cores are CNC-ported and machined to specifications dictated by extensive research and testing. Each set of heads is milled and assembled to the owner’s specifications and utilizes stainless-steel valves. Prices start at a budget-friendly $1,235 (at time of article), with no core charge. Because these heads are a factory casting, they are compatible with all factory components. The upgraded valves are still friendly to smaller-bore combinations (such as 4.8-liter and 5.3-liter blocks).

Precision Race Components

LS6 Stage 1, 6.0-Liter

PRC’s least expensive cylinder head is no slouch, as evidenced by the flow numbers. The base heads come with factory valvesprings, with three different upgrade options. All Stage 1 heads have factory valves and are milled and assembled according to owner specifications. Only new “317” cores are used for the larger chambered 6.0-liter casting, and “243” or “799” cores are used for the LS6. No special components are necessary to use these heads, which are already easy on the wallet with a mere $1,125 price tag (with stock springs). The stock-size valves pose no limitations on bore size.

Precision Race Components

LS6 Stage 2.5, 6.0-Liter

Larger stainless-steel valves help unlock even more flow from the OEM castings, which flow enough air for any smaller-cube build and even some stroker applications though the valves pose no issues with shrouding and bore size. Again, the larger chambers on the 6.0-liter heads are suited for boost, but PRC can mill them down as far as 65 cc. If a smaller chamber is desired, such as for a high-compression head/cam setup, the LS6 can be milled down to 58 cc. Pricing starts at $1,525 with PRC’s double springs.

Precision Race Components

LS6 Stage 3, 6.0-Liter

The 6.0-liter “317” and LS6 “243” (or “799”) castings are pushed to their limit with the largest stainless-steel valves possible, which are ideal for 4-inch bores. The larger chambers on the 6.0-liter heads are ideal for strokers and boost, meanwhile the LS6 heads are best suited for naturally aspirated and nitrous setups. The large valves make a 3.90-inch-or-larger (emphasis on the larger) bore a requirement. With so many upgrades it is no wonder these heads command a price tag of $1,925 (including PRC double valvesprings).

Precision Race Components

215 cc

Don’t be deceived by the small runner sizes, these heads flow serious air. Whether a stump-puller 408 is your objective, or a stock bottom-end race car that will surpass Texas Speed’s record of 9.82 (using these heads), these aftermarket heads can support it. The conservative valve sizes are intended to accommodate small bores (and stock cubic inches) without inhibiting flow. These heads are compatible with factory rockers and other equipment. However, roller rockers are recommended to reduce wear with bronze valveguides (powder metal guides are also available). With PRC’s standard .650-inch-lift springs, these heads start at $2,200.

Precision Race Components

227 cc

This head was specifically designed for maximum-effort smaller-cube combinations. The larger intake runner doesn’t hit its stride until high lift, considerably surpassing the 215-cc head at .650-inch lift (going all the way to 330 cfm). The 227 is designed for a 3.90- to 4.00-inch bore and is compatible with stock rockers and other components (just like the 215-cc); an upgrade to powder metal valveguides is recommended with stock rocker arms. Base price for the 227-cc head is $2,200, which comes assembled with .650-inch-lift PRC valvesprings.

Precision Race Components

237 cc

Based on the same aftermarket casting as the 215- and 227-cc heads, the 237-cc version is made for 4-inch-and-larger bores. From radical 370- to 376-ci combos to strokers, PRC’s highest flowing cathedral port handles them all in stride. The massive 2.10-inch intake valves provide incredible high-end capabilities that few other cathedral ports can offer, perfect for big cubic inches and boost. Just like the other versions, the 237-cc is compatible with factory rockers and other equipment. Despite its flow capabilities, the price tag is still a mere $2,200 with the standard .650-inch-lift PRC springs.

This Tech Tip is From the Full Book,HIGH-PERFORMANCE GM LS-SERIES CYLINDER HEAD GUIDE. For a comprehensive guide on this entire subject you can visit this link:

LEARN MORE ABOUT THIS BOOK HERE

SHARE THIS ARTICLE:Please feel free to share this article on Facebook, in Forums, or with any Clubs you participate in. You can copy and paste this link to share: https://lsenginediy.com/ultimate-ls-cathedral-port-cylinder-heads-guide/

Total Engine AirFlow

Includes:

LS2/LS6 Stage 1

LS2/LS6 Stage 2

Total Engine Airflow (TEA) began in the early 1990s in Bowling Green, Kentucky, and established itself as a premier center for cylinder head research and development. The company has since been moved to Ohio, working closely with sister company Trick Flow. Years of flow bench and dyno testing have helped shape the CNC-machining design of cylinder heads and manifolds. In addition to its regular line of CNC-ported LS heads, TEA also offers custom porting options including factory castings such as the L92/LS3 and various cathedral port heads. Customized performance air-flow solutions are also available. (Photos Courtesy Total Engine Airflow)

Total Engine AirFlow

LS2/LS6 Stage 1

TEA’s Stage 1 program takes the customer-supplied “243” or “799” casting to the next level with a custom four-angle valve job, CNC porting, hand blending of the port and valve job, and back-cut intake valves. Stock valves keep cost down and low- to mid-lift flow up, with the added benefit of small-bore (4.8 and 5.3-liter) compatibility. Because these are stock castings, there are no special components necessary. Many options are available, such as milling to decrease the size of the combustion chambers. Fully assembled with .650-inch-lift dual valvesprings, the Stage 1 heads cost only $1,199 (with a customer-supplied core).

Total Engine AirFlow

LS2/LS6 Stage 2

The Stage 2 program is TEA’s most powerful stock-casting cathedral port. The biggest difference between the Stage 1 and the Stage 2 is the use of larger Ferrea valves and accompanying valve job, which was developed on the Trick Flow Specialties (TFS) 215-cc head. Just like the Stage 1, the 243 or 799 casting receives full CNC porting of the runners and hand blending of the port and valve job. A 3.90-inch-or-larger bore is recommended, and no other special requirements or components are necessary with Stage 2 heads. $1,399 buys you the CNC porting, valve job, and assembly with custom PAC dual .650-inch springs and titanium retainers.

Trick Flow Specialties

Includes:

GenX 205

GenX 215

GenX 220 for LS1

GenX 220 for LS2

GenX 225

GenX 235

GenX 245

265 cc

TFS began in 1983 in Ohio, making big-block Ford cylinder heads, but has since branched out to many Chevy applications and even camshafts, intake manifolds, and other engine components. While it were not the first on the scene with an aftermarket LS head, its cathedral offering is considered to be one of the best and was influential on designs thereafter. This well-thought-out design also carries into various packages, with carefully selected camshaft profiles and quality components to make installations trouble-free. Look for TFS to continue to push the envelope with its designs, including an LS3 casting.

Trick Flow Specialties

GenX 205

These heads are designed specifically for truck engines such as the small-bore 4.8- and 5.3-liter, though they could also be useful in a 5.7-liter looking for maximum torque. The 2.00-inch valves accommodate the smaller bores; however, the rest of the head is CNC-ported to facilitate great flow. The chambers are CNC-machined and bowl-blended to refine the shape, yet are stock size to maintain compression. Unlike their larger cousins, these heads have powdered metal valveguides to make them friendly to factory rocker arms. To further help cut costs, the GenX heads are compatible with factory valve covers, sensors, etc. Fully assembled this fresh casting goes for $1,995 (a pair) through Summit Racing and other dealers.

Trick Flow Specialties

GenX 215

For your typical head/cam LS1 the TFS 215 is hard to beat, with great top-end flow and torque. This is a smart choice for any 3.90-inch bore from mild to wild. The 13.5-degree valve angle means increased piston-to-valve clearance, decreased shrouding, and great midlift flow. CNC-ported intake and exhaust runners with CNC-machined and bowl-blended chambers make this a high-performing head. Roller rock ers are a must with the bronze valve-guides. All other OEM components bolt right on, including center-bolt valve covers. Fully assembled, the 215s cost $2,396 per set from Summit Racing.

Trick Flow Specialties

GenX 220 for LS1

These ascast heads offer all the great features and nearly the performance of the CNC-ported heads, but at a better price. From the 13.5-degree valve angle to the raised valve cover rail, relocated spark plugs, and rigid casting design, these heads have it all. Like the 215s, roller rockers are required. A 3.90-inch bore is also a requirement, with no other special considerations. Fully assembled, a pair of GenX 220s go for $1,700 through Summit Racing.

Trick Flow Specialties

GenX 220 for LS2

Just like the LS1 version these Fast As Cast heads offer all of the great features of the 13.5-degree casting, but in an affordable package. The LS2 version boasts larger intake valves for the 4.00-inch bore and a slightly larger chamber. Roller rockers are required, with no other special needs. Just like the LS1 version, these heads cost $1,700 per pair, fully assembled.

Trick Flow Specialties

GenX 225

The GenX 225 picks up where the 215 head left off, adding greater volume and flow; best suited for 4-inchor-larger bores (though it can fit a 3.90-inch bore):. The substantial capabilities of this fully CNC-ported head can keep up with strokers and forced induction, while also working for some stock cubic-inch combos. Again, this casting sports a 13.5-degree valve angle, raised valve cover rails, and optimized spark plug location. Just as with the 215, roller rockers are required. For $2,396, these heads come fully assembled and ready to bolt onto any Gen III or IV with factory components and fasteners.

Trick Flow Specialties

GenX 235

The TFS 235s come in several varieties, from fully CNC-ported to bare and ascast. The large valves and chambers are designed for 4.030-inch-and-larger bore, which makes them appropriate on high-boost LQ9- and LS3-based combos or for larger-cube street engines. Built with these applications in mind, TFS offers a 6-head-bolt option for LSX blocks. Since the 235s come from the same casting as the smaller versions, they also have a 13.5-degree valve angle, raised valve cover rails, and revised spark plug location. Factor in a set of roller rockers when budgeting for the $2,450 (fully assembled) price tag.

Trick Flow Specialties

GenX 245

The 245-cc GenX head pushes the limits of the cathedral port casting, utilizing massive intake valves that rival rectangular ports, making it suitable for large-bore applications only (though it fits a 4.030-inch). CNC-ported runners and CNC-machined chambers (with bowl-blending) facilitate massive flow, and the 6-bolts-per-cylinder head bolt provision is standard for better clamping with aftermarket blocks. Just like the others, the 245s feature a 13.5-degree valve angle and raised valve cover rails to accommodate the required aftermarket roller rockers. An optional nitrous exhaust port can increase flow to 290 cfm at .600-inch lift. The added machine work puts this head at a starting price of $1,326 (each) when fully assembled with the standard 1.300-inch-diameter dual valvesprings, though Total Engine AirFlow sells this head with other spring options.

Trick Flow Specialties/Total Engine AirFlow

265 cc

TEA CNC-ports the Trick Flow casting to a massive 265 cc to make it an all-out drag head, taking the already impressive 245-cc head and injecting it with steroids. Built for large-lift camshafts and high RPM, this head comes with massive PAC valvesprings, competition 55-degree valve job, and titanium intake valves. Titanium or inconel exhaust valves are optional upgrades to the standard stainless-steel valves from Victory-1. Optional nitrous exhaust ports hit an unbelievable 306 cfm at 1.00 inch of lift. This head comes only with LSX-style 6-bolts-per-cylinder head bolt provisions for aftermarket blocks because a 4.155-inch bore is required. The TFS casting, of course, has a 13.5-degree valve angle and raised valve cover rails to accommodate the required aftermarket roller rockers. These heads start at $3,950 for the pair (assembled).

West Coast Cylinder Heads

Includes:

Edelbrock 4.8/5.3-Liter

Edelbrock LS1, 215 cc

Warhawk, 15-Degree, CNC

Edelbrock LS2, 245 cc

WCCH is quickly becoming one of the foremost designers of CNC programs for aftermarket LS castings, though it has its roots in programs for OEM castings. Both the street and race crowd are well satisfied with WCCH’s All Pro, Brodix, Edelbrock, and factory designs. Though West Coast has been machining heads for more than 23 years in Southern California, with various small- and big-block applications in all forms of motorsports and street performance, the LS market is quickly taking over the business. (Photos Courtesy West Coast Cylinder Heads)

West Coast Cylinder Heads

Edelbrock 4.8/5.3-Liter

Built for the popular 4.8- or 5.3-liter truck engines, WCCH uses a custom CNC program on Edelbrock’s Pro Port casting to create a torquey, small-runner design with great low- and mid-lift flow numbers. The Edel-brock casting is compatible with factory rockers and other equipment, and utilizes the stock LS1 valve angle. As you’d expect from a CNC-ported aftermarket casting these heads go for $2,340 fully assembled.

West Coast Cylinder Heads

Edelbrock LS1, 215 cc

Starting with Edelbrock’s Pro Port casting, WCCH’s CNC program opens the intake runners up to 212 cc, perfect for a stock cubic-inch combo, or even a larger-cube combo where torque is at a premium. The flow numbers are exceptionally high for the runner sizes, which make these heads so versatile. These heads are compatible with all OEM equipment and require a 3.90-inch bore. Just like the smaller truck heads, the 215s come fully assembled for $2,340.

West Coast Cylinder Heads

Edelbrock LS2, 245 cc

On the largest version of the Edelbrock-based trio from WCCH, the large 245-cc intake runners are extremely peaky and benefit large-lift camshafts. Flow continues to rise as it hits .700-inch lift at 337.2 cfm. Though these heads work well with a high-boost 370-ci engine, without forced induction substantial cubes are needed to properly match the large runners. Just like the others, these heads are also compatible with OEM fasteners, sensors, and rocker arms. Despite the added time on the CNC machine, these heads also start at $2,340 with premium upgrades available.

World Products

Warhawk, 15-Degree, CNC

Just like its as-cast cousin, the CNC version flows better as the lift increases past .600 inch and actually hits 330 cfm at .800 inch. On a large-cubic-inch or race application this head has plenty of potential, yet still is completely compatible with factory rockers and other components. However, most likely a solid roller and shaft-mount rockers is the chosen pairing with these heads. An unported version is also available that flows 289 and 204 cfm at .600-inch lift using 235- and 87-cc runners. A 3.90-inch-or-larger bore is required, and most retailers list these heads at $876 each (fully assembled).

Written by Dave Grasso and Posted with Permission of CarTechBooks

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