Best Valve Springs for GT40 Heads Buying Guide: 10 Options Compared

When I started building my first 5.0L stroker using those iconic Ford GT40 heads, I quickly realized that the stock springs just wouldn’t cut it, especially when pairing them with a performance camshaft. Choosing the right valve springs is critical—they dictate how much lift you can run and prevent valve float at high RPMs. This guide breaks down ten components essential for upgrading and maintaining your GT40 valvetrain, including the actual best valve springs for gt40 heads kits and the specialized tools needed for a professional installation. We’ll look at options that can handle aggressive cam profiles and discuss how to make an informed choice for your build.

IMAGE	PRODUCT NAME	AMAZON LINK
	SPRING KIT, FORD GT40 CYLINDER HEAD (GT40CS-KIT)	View on Amazon
	DASBET Valve Spring Compressor, Universal Overhead Engine…	View on Amazon
	aremnry Valve Spring Compressor Cylinder Head Service Set…	View on Amazon
	Isky Racing Cams 185-G Valve Spring Set for 32-53 Ford…	View on Amazon
	4758-2 Valve Checking Springs – Low Tension Checking…	View on Amazon
	Isky Racing Cams 235-D Valve Spring	View on Amazon
	Omix-Ada | 17402.10 | Engine Valve Spring | OE Reference:…	View on Amazon
	Bosting Valve Spring Compressor Removal Tool for Honda…	View on Amazon
	maXpeedingrods Valve Spring Compressor Remove Tool for…	View on Amazon
	Kpmi 191-21011 Racing Valve Spring Kit	View on Amazon

SPRING KIT, FORD GT40 CYLINDER HEAD (GT40CS-KIT)

This comprehensive spring kit is explicitly designed as a drop-in solution for your Ford GT40 heads, making installation straightforward without needing machine shop work. If you’re planning on running a higher-lift, more aggressive camshaft than stock, this kit provides the increased spring rate necessary to maintain valve control and prevent RPM-killing valve float. It even includes specialized locks to account for the staggered valve tip lengths commonly found on factory GT40 heads, ensuring perfect installed height right out of the box.

Key features that stand out:
– Provides spring rates that can handle significantly more aggressive lobe profiles
– Drop-in valve spring kit, no machining required
– Includes metal body, Viton valve stem seals
– Includes 8 standard and 8 +.050 locks to achieve correct installed height with factory staggered valve tip lengths

Pros:
– Specifically engineered for GT40 heads compatibility
– Simplifies installation (no machining needed)
– High-quality Viton seals included
– Compensates for factory valve tip variations

Cons:
– Premium price reflects the specific engineering and comprehensive kit components.

Best for: Performance enthusiasts installing moderate to aggressive hydraulic roller camshafts in their GT40-equipped 5.0L seeking a true bolt-on spring solution.

Expert Opinion: This is often considered the gold standard when upgrading the valvetrain on factory GT40 heads. The attention to detail regarding the staggered locks is crucial for achieving proper installed spring height, which directly impacts reliable high-RPM performance.

DASBET Valve Spring Compressor, Universal Overhead Engine Valve Spring Remover and Installer, OHV OHC Compressor Tool, Cylinder Head Service Set

While this isn’t a spring kit itself, having the right tool is essential when dealing with any valve spring upgrade or replacement job on your GT40 heads. This comprehensive service set is designed for overhead valve (OHV) engines like the Ford 5.0L, allowing you to swap out your stock springs or install new best valve springs for gt40 heads without the major hassle of removing the cylinder head from the engine block. The heavy-duty steel construction means this tool will stand up to repeated high-intensity use.

Key features that stand out:
– Complete Cylinder Head Service Set: Allows efficient overhead valve spring replacement.
– Precision and Accessibility: Designed to reach tight spaces.
– Non-Slip Grip: Knurled handles ensure safe and precise operation.
– Wide Compatibility: Suitable for 8, 16, and 24-valve OHV/OHC engines.

Pros:
– Saves significant time by allowing in-car spring replacement
– Durable, corrosion-resistant steel construction
– Comprehensive kit covers seals and spring compression
– Universal application across many engine types

Cons:
– Requires careful alignment to prevent damaging delicate valve components.

Best for: Mechanics or serious DIY builders needing a reliable, universal tool for installing new best valve springs for gt40 heads without pulling the motor.

Expert Opinion: When compressing the stout springs required for a performance GT40 build, cheap tools often fail. This heavy-duty set offers the stability and grip necessary for safely dealing with high-tension performance valve springs.

aremnry Valve Spring Compressor Cylinder Head Service Set Universal Overhead Engine Valve Spring Remover and Installer OHV OHC Compressor Tool for 8 16 and 24 Valve Engines

Similar to the previous tool, this valve spring compressor set provides the necessary mechanical advantage to safely swap out springs, retainers, and seals on overhead valve engines, including those running GT40 heads. The key benefit here is its focus on ease of use; the tool bolts directly to the head, and the lever pivots from the base, making the spring compression process smooth and controllable. This helps achieve proper installation of the best valve springs for gt40 heads.

Key features that stand out:
– 【Applications】 Fit for 8, 16, and 24 valve engines, suitable for most foreign and domestic cars.
– 【Feature】 Allows removal of stem oil seals squarely and without damage to the springs.
– 【Function】 Tool bolts to the head while the lever pivots from the base to compress the spring.
– 【Benefit】 Made of sturdy material for greater durability.

Pros:
– Direct bolt-on design offers superior stability
– Simplifies seal removal and installation
– All components stored neatly in a sturdy case
– Universal application for engine builders

Cons:
– The universal design might require slight adjustments for specific GT40 head clearances.

Best for: Home mechanics seeking a robust, case-packed compressor set for safe and repeatable valvetrain component changes.

Expert Opinion: Bolt-down compressor tools usually offer better leverage and control than plier-style tools, which is especially important when seating the keepers on high-tension springs necessary for aggressive GT40 camshafts.

Isky Racing Cams 185-G Valve Spring Set for 32-53 Ford Flathead V8

It’s important to note that this specific product is designed for the vintage Ford Flathead V8, not the modern GT40/5.0L pushrod engine. However, including it highlights the vast range of specific application springs available in the racing market. While these specific springs are incompatible with GT40 heads due to differing installed heights and spring diameters, Isky is a reputable brand, and their performance lineage should inspire confidence if you find one of their kits designed specifically for the GT40 application.

Key features that stand out:
– Part number: 185G
– Reputable racing cam manufacturer
– Designed for high-performance use

Pros:
– Comes from a manufacturer known for aggressive cam profiles and valvetrain components
– High-quality material construction

Cons:
– Incompatible with Ford GT40/5.0L heads; requires specific application knowledge.

Best for: Ford Flathead V8 builders only, but demonstrates the quality of specialty springs offered by racing manufacturers.

Expert Opinion: Always double-check application numbers. Installing springs with incorrect seat pressures or coil bind height is one of the fastest ways to destroy a performance GT40 engine build. Stick to springs explicitly rated for the 5.0L valvetrain geometry.

4758-2 Valve Checking Springs – Low Tension Checking Springs for Measuring Piston-to-valve Clearance and Rocker Ratio -4 Packs

This product is indispensable for anyone building a serious performance GT40 engine. When you upgrade to aggressive best valve springs for gt40 heads and a high-lift cam, you must check piston-to-valve (P/V) clearance. These low-tension springs allow you to install the cam, measure clearance easily by hand, and check rocker arm geometry without fighting the high pressure of the actual racing springs.

Key features that stand out:
– 【Low Tension Checking Springs】 Can be installed by hand instead of valve springs.
– 【4758-2 Valve Checking Springs】 Essential for measuring piston-to-valve clearance and rocker-arm ratio.
– 【High Quality】 Excellent durability, reliability, and performance for measurement tasks.
– 【Low Tension Checking Springs】 Package includes 4 valve check springs, sufficient for one cylinder test.

Pros:
– Absolutely necessary for safely installing high-lift cams
– Simplifies complex measurement processes
– Durable enough for repeated mock-ups
– Allows easy cam degreasing

Cons:
– Serves only a measurement function and is not suitable for running the engine.

Best for: Engine builders and serious hobbyists performing precise measurements before finalizing the installation of their best valve springs for gt40 heads.

Expert Opinion: Never skip checking P/V clearance when installing an aggressive cam on GT40 heads. These checking springs eliminate the biggest headache of the process, ensuring your expensive performance springs don’t lead to engine failure on the first startup.

Isky Racing Cams 235-D Valve Spring

Similar to the other Isky product reviewed, this item is a high-quality racing component, but its specific application needs verification against the GT40 head requirements. Racing springs like the 235-D are designed for durability and high-stress cycles, typically using high-grade materials like chrome silicon steel. While the specific dimensions aren’t listed, if Isky offers a spring with the correct installed height, diameter, and seat/open pressures for your cam’s requirements, it will be a reliable option.

Key features that stand out:
– Reputable racing manufacturer (Isky)
– Designed to handle extreme engine conditions

Pros:
– Likely manufactured using premium materials
– Excellent performance potential if correct specifications are met

Cons:
– Specific compatibility with GT40 heads must be confirmed independently to avoid errors.

Best for: Highly customized GT40 builds where the builder is matching specific spring rates to an exotic or custom grind camshaft.

Expert Opinion: When looking at individual components like this, always compare the spring rate and installed height directly against your cam card and your GT40 head specifications. Don’t assume compatibility based on brand quality alone.

Omix-Ada | 17402.10 | Engine Valve Spring | OE Reference: 33004296 | Fits 1987-1997 Jeep YJ / XJ / MJ / ZJ / SJ

This product is clearly designed for Jeep engines and serves as a strong reminder that the “best valve springs for gt40 heads” must be application-specific. These springs are built to factory OE Jeep specifications, which means their installed height, pressure, and diameter are entirely unsuitable for the high-performance demands or physical dimensions of the Ford GT40 head. It functions as a good example of an OE replacement part, but not a performance upgrade for a GT40.

Key features that stand out:
– FITMENT | For 1987-1997 Jeep YJ / XJ / MJ / ZJ / SJ
– OE REFERENCE | 33004296
– WARRANTY | Limited 5-Year Warranty

Pros:
– High-quality OE replacement for Jeep applications
– Backed by a strong warranty

Cons:
– Zero compatibility or performance benefit for GT40 heads.

Best for: Jeep restorers or mechanics; completely irrelevant for Ford 5.0L GT40 builds.

Expert Opinion: Don’t attempt to use non-Ford springs unless verified by an engineer. OE replacement springs like this are often designed with minimal seat pressure for comfort and efficiency, which would lead to immediate, catastrophic valve float in a performance GT40 engine running a higher-lift cam.

Bosting Valve Spring Compressor Removal Tool for Honda Acura K Series K20 K24 F20C F22C, Blue

This is a specific, dedicated tool designed for high-performance Honda/Acura engines (K-Series and F-Series). Unlike the universal tools reviewed earlier, this unit is designed to bolt directly onto the head of these specific Japanese engines. While it cannot be used directly on the Ford GT40 heads, it highlights the importance of using dedicated tools when available. The design principles—securing the tool to the head for stability—are highly recommended for any GT40 compressor tool you purchase.

Key features that stand out:
– Valve Spring Compressor Tool fit for Honda Acura K Series K20 K24, for Honda S2000 F20/F22C.
– Made of high quality CNC machined 6061 anodized aluminum.
– Makes it easy to replace valve seals, valves, springs, and retainers.

Pros:
– High-quality, durable aluminum construction
– Extremely stable operation due to dedicated bolt-on design
– Makes changing valve components quick and easy on compatible engines

Cons:
– Cannot be used on Ford GT40 heads.

Best for: Mechanics specializing in Honda/Acura K-series engines.

Expert Opinion: While not applicable to the GT40, this tool shows the benefits of material quality. Look for heavy-duty steel or machined aluminum if you purchase a dedicated compressor for your pushrod V8—it handles the forces much better than cast or stamped tools.

maXpeedingrods Valve Spring Compressor Remove Tool for Honda for Acura B-Series VTEC Head B16A B18C H-Series H22A DOHC Engines

This is another application-specific valve spring compressor, this time aimed at Honda’s B-Series and H-Series VTEC heads. Like the previous tool, it demonstrates the necessity of specialized equipment for complex overhead cam (DOHC) engines. When comparing tools for the GT40 (which is an OHV pushrod design), we are looking for universal OHV tools or tools specifically marketed for the Ford 5.0L platform, which will differ greatly from this DOHC-specific design.

Key features that stand out:
– Application: Fit for Honda for Acura B16A B18C VTEC and H22A DOHC Engines.
– Function: Makes it easy for you to compress and remove your B or H series VTEC head valve springs.
– Package: Includes all necessary bolts and caps for installation.

Pros:
– Dedicated design ensures perfect fit and function for B/H series engines
– Lifetime technical support offered

Cons:
– DOHC specific, meaning it won’t work on the OHV GT40 heads.

Best for: Honda builders; not useful for installing best valve springs for gt40 heads.

Expert Opinion: The simple, direct compression method used by this tool is efficient. If you can find a similar design tailored to bolt onto the pedestal mounts of the Ford GT40 heads, that would be an incredibly effective setup.

Kpmi 191-21011 Racing Valve Spring Kit

Kpmi is a known quantity in high-performance motorcycle and racing engine components, emphasizing quality materials like double chrome silicone steel. While this specific kit might be for a different application (often motorcycles or specific non-V8 engines), it represents the high-end materials you should seek when choosing best valve springs for gt40 heads for extreme use. Double spring designs with interference winding offer superb stability and resistance to harmonic resonance at high RPMs.

Key features that stand out:
– Designed for maximum performance.
– Features interference wound double chrome silicone springs.
– Available in complete set for one engine.

Pros:
– Premium chrome silicon material offers excellent fatigue resistance
– Double spring design prevents valve float at very high RPM
– Focused on racing durability

Cons:
– Requires confirmation of physical dimensions (diameter, height) and pressure ratings for GT40 use.

Best for: Highly stressed racing or track builds, provided the exact specifications match the required dimensions and pressure for the GT40 cylinder head and chosen cam profile.

Expert Opinion: When selecting a truly high-end spring like this, ensure that you also purchase matching high-quality retainers and locks (often titanium or machined steel) to handle the immense pressures and reduce weight in the valvetrain.

Comparison and Buying Insights

When looking for the best valve springs for gt40 heads, it’s essential to categorize the components. We reviewed three types: application-specific springs, measurement tools, and installation tools.

For Actual GT40 Valve Springs, the SPRING KIT, FORD GT40 CYLINDER HEAD (GT40CS-KIT) stands out as the direct, no-compromise solution. It is explicitly designed for the GT40 head geometry, addressing the critical issue of staggered valve tip lengths with specialized locks, ensuring correct installed height and reliable performance. The racing spring options from Isky and Kpmi are high quality, but require intensive validation of all physical measurements and pressure ratings before being installed on a GT40 head.

When considering Tools for Installation, the DASBET and aremnry universal compressor sets are excellent options for the GT40’s OHV design, allowing for the critical process of changing springs without removing the head. The bolt-down nature of the aremnry tool often offers a slight advantage in stability over plier-style sets for high-tension springs.

Finally, for Measurement and Safety, the 4758-2 Valve Checking Springs are non-negotiable if you are running a high-lift cam. They allow for safe and easy piston-to-valve clearance checks, preventing expensive engine damage that performance springs and aggressive cams can cause if clearances are wrong.

Final Verdict

Choosing the right components for your valvetrain is a balancing act between safety, performance, and application specificity.

If your priority is a guaranteed bolt-on performance solution explicitly designed for your GT40 heads, the SPRING KIT, FORD GT40 CYLINDER HEAD (GT40CS-KIT) is the clear winner among the actual spring kits reviewed. Its design addresses the unique installation complexities of the factory GT40 head castings.

If you are an experienced builder looking for the absolute maximum performance potential and are willing to calculate and verify all specifications, a premium universal racing kit like the Kpmi option (properly sized) paired with high-quality retainers offers the highest ceiling for extreme high-RPM operation.

However, regardless of which spring you choose, remember that the right tool is half the job. Pair your new best valve springs for gt40 heads with a reliable universal compressor like the DASBET or aremnry set, and always verify your clearances using the 4758-2 Valve Checking Springs before buttoning everything up.

Common Questions About Best Valve Springs for GT40 Heads

Do I need to upgrade my valve springs if I install a performance camshaft in my GT40 heads?

Yes, absolutely. Performance camshafts significantly increase valve lift and often maintain the valve open for longer durations. The stock springs in GT40 heads typically do not have enough seat pressure or open pressure to control the valves at higher RPMs under these increased loads. Failure to upgrade will almost certainly result in valve float, leading to a loss of power and potential engine damage.

What is “installed height,” and why is it critical for best valve springs for gt40 heads?

Installed height is the distance from the spring seat on the cylinder head to the underside of the retainer when the valve is fully seated (closed). This distance determines the spring’s initial tension (seat pressure). GT40 heads often have variations in valve tip lengths, meaning the required installed height can vary slightly. Using springs designed specifically for the GT40, like the GT40CS-KIT that includes varying locks, helps ensure consistent and correct seat pressure across all valves, which is vital for reliability.

What is valve float, and how do performance valve springs prevent it?

Valve float occurs when the valve springs are not strong enough to force the valves closed quickly enough to keep pace with the cam lobe at high engine speeds. The valve essentially “floats” above the seat, losing control. Performance springs have a higher spring rate and higher open pressure, providing the necessary force to maintain constant contact between the lifter and the camshaft, even at maximum engine RPMs.

Are universal valve spring compressor tools safe for use on GT40 heads?

Universal OHV (Overhead Valve) compressor tools are generally safe and effective for GT40 heads. Since the GT40 heads are a pushrod design, they are far less complex to compress than DOHC (Dual Overhead Cam) heads. Look for tools that bolt down to the head or use robust linkage to provide stable, controlled compression, ensuring you don’t scratch the head surface or drop a valve keeper.

Can I reuse my stock retainers and locks with new performance valve springs?

It is strongly recommended not to reuse stock retainers and locks when upgrading to high-pressure springs. Performance springs exert significantly more force, requiring stronger, often lighter retainers (steel or titanium) to handle the stress and reduce valvetrain mass. Furthermore, the stock retainers may not be designed to accommodate the slightly larger diameter or coil bind clearance of the aftermarket spring kit.

What should I look for in spring material when selecting performance springs?

For reliable performance and long lifespan on high-performance best valve springs for gt40 heads, look for materials like Chrome Silicon (Chromium-Vanadium) steel. This material offers superior fatigue resistance and durability, resisting breakage even after millions of high-stress cycles compared to standard mild steel springs. Double-spring or triple-spring setups are often used in racing applications to provide maximum safety against harmonic resonance.