A strong LS3 cylinder-head choice matches your engine configuration and build goals, whether you need a stock-style replacement or a performance upgrade. Frankenstein M311 273cc LS3 Heads lead for performance builds with fully CNC-ported 273cc intake ports, an 11-degree valve angle, and PAC .700-inch springs. For another CNC-ported option, BTR CVH LS3 Heads report more than 370 CFM at .650-inch lift, but their canted-valve design and minimum 3.820-inch bore requirement make compatibility checks essential.
Stock-style buyers can consider the remanufactured 823 pair, while bare aluminum pairs suit projects where assembly components are handled separately. The six options differ in port and chamber dimensions, assembly status, and included valvetrain parts, so verify your engine, bore, and build requirements before choosing.
Frankenstein M311 273cc LS3 Heads are the strongest overall pick for an LS3 performance build because they combine fully CNC-ported 273cc intake ports, 112cc exhaust ports, an 11-degree valve angle, 68cc chambers, and PAC .700-inch springs in a performance pair. BTR CVH LS3 Heads are a strong alternative for buyers prioritizing a reported airflow figure, but their canted-valve layout requires a compatible engine setup and at least a 3.820-inch bore. For stock-style replacement, consider the remanufactured 823 pair instead.
Our Top Picks
Best OverallFully CNC-ported 273cc intake and 112cc exhaust ports, 11-degree valve angle, 68cc chambers, and PAC .700-inch springs target performance builds.
View on Amazon
Highest Reported AirflowThe assembled pair has CNC-finished 260cc runners, 64cc chambers, and reported intake airflow above 370 CFM at .650-inch lift.
View on Amazon
Best Stock-Style PairThis remanufactured pair includes rocker arms and pedestal stands, with pressure testing, replacement guides as needed, and a 70cc chamber.
View on Amazon- Largest Intake Runner IMOOA LS3 Bare Pair
Compare LS3 Head Options and Included Components
| # | Product | Buy |
|---|---|---|
| 1 | 1. Frankenstein M311 LS3 HeadsBest Overall | View on Amazon |
| 2 | 2. BTR CVH LS3 HeadsHighest Reported Airflow | View on Amazon |
| 3 | 3. Remanufactured 823 Head PairBest Stock-Style Pair | View on Amazon |
| 4 |  4. IMOOA LS3 Bare PairLargest Intake Runner | View on Amazon |
| 5 |  5. PUFFIS LS3 Bare HeadBare LS3/L92 replacement head | View on Amazon |
| 6 |  6. Remanufactured 823 Single HeadSingle stock-style replacement head | View on Amazon |
Detailed Reviews: Best Heads For Ls3
#1 · Best Overall
1. Frankenstein M311 LS3 Heads
Best for: High-lift performance LS3 builds.
Why it ranks #1: Fully CNC-ported 273cc intake and 112cc exhaust ports, 11-degree valve angle, 68cc chambers, and PAC .700-inch springs target performance builds.
Custom PAC .700-inch lift dual valve springs are paired with a fully CNC-ported 273cc intake runner, making this Frankenstein M311 pair a performance-focused choice for LS3 builders planning a high-lift valvetrain. The 11-degree valve angle and 68cc chambers further define its configuration.
The 5-axis CNC-ported 273cc intake and 112cc exhaust ports are hand-blended and deburred, giving buyers specific airflow-oriented port details to evaluate for a performance build. Custom PAC springs are rated for .700-inch lift and pair with lightweight titanium retainers, so the valvetrain specification is relevant when matching cam and component plans. Black nitride stainless severe-duty valves complete the listed valvetrain package; the 68cc chamber and 11-degree angle remain key setup considerations.
- Fully CNC-ported 273cc intake and 112cc exhaust ports
- Custom PAC .700-inch lift dual valve springs
- Lightweight titanium retainers and black nitride stainless valves
- 11-degree valve angle with 68cc chambers
- The .700-inch spring specification makes this a specialized choice for builds that do not need high lift.
Skip it if you want an OE stock-style remanufactured head with rocker arms included; the Amazon Renewed GM 823 assembly lists them.
Choose the M311 pair for an LS3 performance build whose valvetrain plan calls for its .700-inch PAC springs and CNC porting. Match the 68cc chamber and 11-degree geometry to the intended engine setup.
Full product details
| Brand | Michigan Motorsports |
|---|---|
| Item model number | MM113004-Pair |
| Manufacturer | Frankenstein Engine Dynamics |
| Part Number | MM113004-Pair |
| Model | Frankenstein Boost Series LS3 Cylinder Heads |
Listed on Amazon as: Frankenstein M311 273cc Monster Series LS3 Cylinder Heads – 11 Degree Valve Angle, Fully CNC Ported with PAC .700" Springs, Titanium Retainers – Performance Pair for GM LS3 Engines
View on Amazon#2 · Highest Reported Airflow
2. BTR CVH LS3 Heads
Best for: Canted-valve performance builds.
Why it ranks #2: The assembled pair has CNC-finished 260cc runners, 64cc chambers, and reported intake airflow above 370 CFM at .650-inch lift.
The canted-valve layout pairs with BTR’s CNC-finished 260cc LS3-style rectangle intake runners, giving compatible Gen III and Gen IV LS builders a distinct cylinder-head configuration. The assembled pair includes finished valve guides and seats, while BTR reports more than 370 CFM of intake airflow at .650-inch lift.
Each head has a finished 64cc chamber and requires a minimum 3.820-inch bore, so bore compatibility is a key planning check before an LS3-style build. The six-bolt pair arrives assembled with finished guides and seats, reducing the component assembly work compared with bare heads. BTR’s reported airflow figure applies at .650-inch valve lift; buyers should account for that lift condition when evaluating the head for their intended valvetrain and engine setup.
- Canted-valve arrangement for a compatible Gen III or Gen IV LS V8
- CNC-finished 260cc LS3-style rectangle intake runners
- Finished 64cc combustion chambers
- Assembled six-bolt pair with finished guides and seats
- Requires a minimum 3.820-inch cylinder bore, limiting fit on smaller-bore combinations.
Skip it if you need a stock-style remanufactured pair with rocker arms included; the Amazon Renewed GM 823 assembly supplies them.
Choose this pair for a compatible Gen III or Gen IV LS build seeking canted valves and CNC-finished rectangle ports. Check the 3.820-inch minimum bore and intended valve-lift setup before selecting it.
Full product details
| Brand | Michigan Motorsports |
|---|---|
| Item Weight | 30 pounds |
| Item model number | BTR-CVH3C-6A-Pair |
| Manufacturer | Brian Tooley Racing |
| Part Number | BTR-CVH3C-6A-Pair |
| Model | LS3 Canted Valve Cylinder Heads |
| Dimensions | 24 x 13 x 11 inches |
| Additional Information | Important Information Proposition 65 Warning for California Consumers WARNING: Cancer and Reproductive Harm – www.P65Warnings.ca.gov |
Listed on Amazon as: BTR Brian Tooley Racing CVH LS3 CNC-Ported Canted Valve Cylinder Heads Pair | Fits Gen III IV LS V8 Engines with LS3 Rectangle Port Components and 3.820-Inch Bore | Assembled 64cc Chambers
View on Amazon#3 · Best Stock-Style Pair
3. Remanufactured 823 Head Pair
Best for: Remanufactured stock-style pair.
Why it ranks #3: This remanufactured pair includes rocker arms and pedestal stands, with pressure testing, replacement guides as needed, and a 70cc chamber.
Remanufacturing includes hot-tank cleaning, pressure testing, and a completed valve job, giving LS3 and L92 rebuilders a processed pair rather than bare castings. The listing specifies rocker arms and pedestal stands, making this assembly relevant when a stock-style head setup is the intended direction.
The cleaning and pressure test address casting condition before final assembly, while new valve seats and stem seals are installed as necessary and guides are replaced as necessary. A multi-angle valve job and vacuum-tested seals support the stated compression-focused service process. The pair is described as OE stock LS 6.0L/6.2L heads with rocker arms and pedestal stands, so it favors a stock-style rebuild workflow over a bare-head performance-port selection.
- Pair of remanufactured OE stock LS3/L92 6.0L and 6.2L assemblies
- Hot-tank cleaned and pressure tested
- Valve job with required angles and vacuum-tested seals
- Includes rocker arms and pedestal stands
- Stock-style 257cc intake-port volume is less than the PUFFIS head’s listed 260cc runner volume.
Skip it if you need bare heads for a custom assembly; PUFFIS PFS-PCH-LS3 is listed as a bare cylinder head.
Consider this pair for a stock-style LS3 or L92 rebuild where remanufacturing steps and included rocker arms and pedestal stands suit the workflow. Confirm that a paired assembly is what your project requires.
Full product details
| Brand | Amazon Renewed |
|---|---|
| Item model number | 823 |
| Manufacturer | General Motors |
| Part Number | 823 ; 821 ; 5364 |
| Model | Cylinder Head |
Listed on Amazon as: GM LS3 L92 6.0L 6.2L Cylinder Heads REMANUFACTURED 823 Square Port Assembly w/Rocker Arms PAIR 823 ; 821 ; 5364 ; 12600936 ; 12629062 ; 126269064 SET (Renewed)
View on Amazon#4 · Largest Intake Runner
4. IMOOA LS3 Bare Pair
Best for: Bare-head replacement projects.
Why it ranks #4: The bare aluminum pair lists 265cc intake runners, 70cc chambers, bronze valve guides, and ductile iron seats for compatible LS3 and L92 engines.
A 70cc combustion chamber and 265cc intake runner define this bare aluminum pair for compatible GM LS3, L92, 6.0L, and 6.2L applications. Bronze valve guides and ductile iron seats are included, giving rebuilders specified wear-related components while leaving assembly work to the engine shop.
The 2.165-inch intake and 1.590-inch exhaust valve diameters provide concrete dimensions for checking a planned combination, while the listed 70cc chamber and 265cc runner help distinguish its port and chamber sizing. Because these are bare heads, the buyer must plan the remaining assembly and valvetrain work rather than expect a ready-to-install assembled pair. High-grade aluminum construction, bronze guides, and ductile iron seats are specified for the head’s construction.
- Compatible with GM LS3 and L92 6.0L and 6.2L engines
- 70cc combustion chambers
- 265cc intake runners with 2.165-inch intake valves
- Bronze valve guides and ductile iron valve seats
- Supplied as bare heads, so they are not a fully assembled installation-ready pair.
Skip it if you want rocker arms and a remanufactured stock-style assembly; the Amazon Renewed GM 823 pair includes rocker arms.
This pair suits builders sourcing bare heads for a compatible LS3 or L92 6.0L or 6.2L project. Choose it only if your workflow includes the remaining head assembly and installation decisions.
Full product details
| Brand | IMOOA |
|---|---|
| Item model number | MTD0199*2 |
| Manufacturer | IMOOA |
| Part Number | MTD0199*2 |
| Model | Cylinder Head |
Listed on Amazon as: One Pair Bare Cylinder Heads For GM LS3 L92 6.0L 6.2L Aluminum
View on Amazon#5
5. PUFFIS LS3 Bare Head
Best for: Bare LS3/L92 replacement head.
Why it ranks #5: This bare aluminum head has rectangular intake ports, oval exhaust ports, 260cc runners, and 70cc chambers for compatible LS3-style applications.
Rectangular intake ports and oval exhaust ports give this bare aluminum head a specified LS3/L92-style port layout for compatible 6.0L and 6.2L applications. Its 70cc chamber and 260cc intake runner provide sizing details for builders selecting a replacement casting for a custom assembly.
The standard port locations are identified for compatible LS3/L92-style applications, helping buyers evaluate layout before planning installation. A 70cc chamber and 260cc intake runner offer concrete sizing information, while the non-CNC-machined chambers distinguish its finish from CNC-finished alternatives. As a bare head, it suits projects where the builder is handling assembly and component selection; verify the engine configuration and head specifications before committing to the fit.
- Compatible with GM LS3/L92-style 6.0L and 6.2L applications
- Rectangular intake and oval exhaust ports
- 70cc combustion chamber with 260cc intake runner
- Natural aluminum head with standard port locations
- Combustion chambers are non-CNC-machined.
Skip it if you need an assembled pair with rocker arms; the Amazon Renewed GM 823 pair lists those components.
This is a fit for a builder sourcing a bare LS3/L92-style head and managing assembly independently. Check engine configuration and port specifications, and account for the non-CNC-machined chambers in your plan.
Full product details
| Brand | PUFFIS |
|---|---|
| Item model number | PCH-LS3 |
| Manufacturer | PUFFIS |
| Part Number | PFS-PCH-LS3 |
| Model | PFS-PCH-LS3 |
Listed on Amazon as: Bare Cylinder Head Compatible with GM LS3 L92 6.0L 6.2L, 70cc, 260cc
View on Amazon#6
6. Remanufactured 823 Single Head
Best for: Single stock-style replacement head.
Why it ranks #6: This single remanufactured stock-style head includes rocker arms and a pedestal stand, with a 70cc chamber and 257cc intake port volume.
This remanufactured LS3/L92 head is sold as a single assembly with rocker arm and pedestal stand, enabling a buyer replacing one stock-style 6.0L or 6.2L head to source an assembled unit. Hot-tank cleaning and pressure testing are part of its listed process.
The remanufacturing process includes cleaning, pressure testing, and a valve job with required angles; seals are vacuum tested, and seats or guides are renewed as necessary. Those steps provide a documented service path before final assembly to AERA specifications. Its 70cc chamber and 257cc intake-port volume identify stock-style dimensions, while the single-head format is important for planning: it is not the paired quantity offered by the related renewed set.
- Single remanufactured OE stock LS3/L92 head
- Includes rocker arm and pedestal stand
- Hot-tank cleaned and pressure tested
- Valve job with vacuum-tested seals and AERA-specification assembly
- Sold as one cylinder head, so replacing both sides requires sourcing another head.
Skip it if you need both heads together; the Amazon Renewed GM 823 remanufactured pair is listed as a set.
This suits a stock-style LS3 or L92 repair needing one remanufactured head with rocker arm and pedestal stand. Its single-unit format is the key boundary when planning a two-head replacement.
Full product details
| Brand | Amazon Renewed |
|---|---|
| Item model number | 823 821 |
| Manufacturer | General Motors |
| Part Number | 823 ; 821 ; |
| Model | Cylinder Head |
Listed on Amazon as: GM LS3 L92 6.0L 6.2L Cylinder Head REMANUFACTURED 823 Square Port Assembly with Rocker Arms 823 ; 821 ; 5364 ; 12600936 ; 12629062 ; 126269064 (Renewed)
View on AmazonCheck Bore and Valve-Layout Compatibility
The main compatibility trap is treating every LS3-style head as a direct, interchangeable fit. BTR CVH LS3 Heads specify a minimum 3.820-inch bore and use a canted-valve arrangement, so confirm the block bore and the rest of the engine configuration before ordering. The other listings describe LS3/L92-style or LS3-compatible applications, but their listed fitment language is not a complete confirmation for every block, piston, or vehicle.
A head may physically suit an engine family and still need careful checks against bore, piston clearance, intake and exhaust port layout, and valvetrain geometry. The bare options also differ: IMOOA LS3 Bare Pair lists 265cc runners, while PUFFIS LS3 Bare Head lists 260cc.
Confirm the exact casting or part-number interchange and the complete combination with a qualified engine builder rather than relying on displacement or the LS3 label alone.
Assembled Does Not Mean Ready to Install
An assembled listing can reduce parts sourcing, but it does not establish that a head is ready to bolt onto every engine. Frankenstein M311 LS3 Heads list PAC .700-inch springs and titanium retainers, while BTR CVH LS3 Heads are described as an assembled pair with finished guides and seats. The remanufactured 823 pair includes rocker arms and pedestal stands, and its listing describes inspection and pressure testing.
By contrast, IMOOA LS3 Bare Pair and PUFFIS LS3 Bare Head are bare heads, so buyers must account for the remaining assembly and valvetrain requirements. A common failure mode is assuming that existing springs, pushrods, rockers, or pistons suit a different head’s lift, geometry, or valve layout.
Check cam lift against spring specifications and verify component compatibility as a complete system; the supplied descriptions do not give every clearance or installation requirement.
How to Choose LS3 Cylinder Heads
Port Size and Intended Build
Choose port dimensions to suit the airflow and operating goals of your engine, not simply the largest listed number. The options span 260cc runners on BTR CVH LS3 Heads and PUFFIS LS3 Bare Head, 265cc on IMOOA LS3 Bare Pair, and 273cc intake ports on Frankenstein M311 LS3 Heads. The remanufactured stock-style pair lists a 257cc intake port volume.
These figures describe different designs and do not alone predict power or compatibility. A performance-oriented build may favour the CNC-ported Frankenstein or BTR heads, while a stock-style repair may suit the remanufactured pair.
For a replacement where final port matching and assembly are part of the build, a bare head may make sense. Match port layout and dimensions to the intake, exhaust, displacement, and intended operating range.
Chamber Volume and Engine Combination
Check chamber volume against your pistons and target compression ratio before selecting a head. The listings range from 64cc on BTR CVH LS3 Heads, through 68cc on Frankenstein M311 LS3 Heads, to 70cc on the IMOOA, PUFFIS, and remanufactured options. Chamber size is only one part of the calculation: piston dish or dome, deck height, gasket thickness, and bore also affect the final result.
The smaller listed chambers may appeal to a build designed around that volume, while 70cc options may better suit a combination specified for those chambers. Do not assume that moving from a stock-style head to a smaller chamber is automatically appropriate; calculate the complete engine combination and check piston-to-valve clearance before assembly.
Assembly Level and Included Components
Decide whether you want assembled heads with listed valvetrain parts or bare castings for a custom build. Frankenstein M311 LS3 Heads list PAC .700-inch springs and titanium retainers; BTR CVH LS3 Heads are an assembled pair with finished guides and seats. The remanufactured 823 pair includes rocker arms and pedestal stands, while the single remanufactured head also lists those parts.
IMOOA LS3 Bare Pair and PUFFIS LS3 Bare Head are bare products, so plan for the parts and assembly work your engine requires. A complete performance build may favour the Frankenstein package, while someone replacing a stock-style pair may prefer the remanufactured assembly.
Choose a bare option when you have a specific component plan and can confirm what is and is not supplied.
Which LS3 Heads Should You Choose?
For a performance-focused LS3 build, choose Frankenstein M311 LS3 Heads: their 273cc CNC-ported intake ports, 11-degree valve angle, and PAC .700-inch springs make them the most purpose-built package here. Choose BTR CVH LS3 Heads if their canted-valve layout suits your combination and you can verify the minimum 3.820-inch bore; they report more than 370 CFM at .650-inch lift. For a stock-style replacement pair, Remanufactured 823 Head Pair includes rocker arms and pedestal stands.
If you specifically need bare aluminum castings, IMOOA LS3 Bare Pair offers 265cc runners, while PUFFIS LS3 Bare Head is a single 260cc option. Choose Remanufactured 823 Single Head when replacing one stock-style head.
Confirm fitment and component compatibility before ordering.
Frequently Asked Questions
How do I confirm that an LS3 cylinder head will fit my block and bore?
Confirm the exact engine, bore, and required port and valvetrain compatibility before ordering. The BTR CVH listing specifies a minimum 3.820-inch bore and a canted-valve layout, so verify that your setup accommodates both. For other listings, check fitment details with the seller rather than assuming LS3 naming alone confirms compatibility.
Do LS3 heads arrive assembled, and what valvetrain parts will I still need?
It depends on the listing. The BTR CVH and Frankenstein M311 are described as assembled or as performance packages with specified springs and retainers; the remanufactured 823 pair and single are listed with rocker arms. The IMOOA pair and PUFFIS head are bare.
Check each listing for included parts and confirm what your build still requires.
How should combustion-chamber volume affect compression ratio and piston selection?
Chamber volume affects the space above the piston at top dead center, so it must be considered with piston design and the rest of the engine combination. The listings identify different chamber volumes, including 64cc for BTR and 68cc for Frankenstein. Verify the resulting compression ratio for your specific setup before selecting heads or pistons.
What is the difference between a bare head and an assembled head?
A bare head is listed as a casting, while an assembled head is presented with assembled components or specified included parts. The IMOOA and PUFFIS listings are bare; the remanufactured 823 listings specify rocker arms. Confirm the exact included components for the chosen listing, since the titles do not establish every part needed for installation.
Should I buy a pair or a single replacement head?
Choose a pair when replacing or upgrading both sides, and consider the remanufactured 823 single when replacing one stock-style head. The listings also include a remanufactured 823 pair with rocker arms. Before ordering, confirm that the selected head or pair matches the other side and your engine’s fitment and component requirements.
Final Words
For a performance-focused LS3 build, the Frankenstein M311 is the strongest overall choice in this roundup, while BTR is an alternative if its canted-valve layout and 3.820-inch minimum bore suit your combination. For stock-style replacement, consider the remanufactured 823 pair; choose its single-head listing when replacing one. If you need bare castings, compare the IMOOA pair and PUFFIS single.
Confirm fitment and included components before ordering.
