Speedmaster Cylinder Heads

Speedmaster Cylinder Heads: Engineered for Real-World Performance

When it comes to unlocking more power from a classic V8, few upgrades are as transformative as a set of quality cylinder heads. Speedmaster has built a strong reputation in the performance engine community by delivering well-engineered, broad-coverage cylinder heads that address the needs of street enthusiasts, weekend racers, and serious engine builders alike — all without requiring a premium-brand budget.

Two Distinct Lines: As-Cast and CNC-Ported

Speedmaster structures its cylinder head catalog around two core product families, each aimed at a specific tier of performance:

• As-Cast Cylinder Heads (PCE281 Series): Speedmaster's as-cast heads are designed for entry-level street and strip applications, delivering improved power throughout the rpm range for stronger throttle response and top-end output. They are available in both bare and fully assembled configurations for popular V8 platforms.
• CNC-Ported Cylinder Heads: For builders chasing serious horsepower, Speedmaster's CNC-ported heads take the platform to the next level. Intake runners, exhaust runners, and combustion chambers are CNC-machined to within .002-inch tolerance, with combustion chambers sharing the same volume and runners sharing the same cross-section — ensuring equalized compression and airflow across every cylinder.

Construction and Materials

Speedmaster's aluminum heads are gravity die-cast from heat-treated T6 aluminum. This casting method produces a more uniform, robust structure that eliminates porosity and dimensional inaccuracies. Every head features CNC-finished mounting surfaces and bolt holes for proper sealing, bronze valve guides for durability, a three-angle valve job, ductile iron or flame-hardened valve seats compatible with all fuel types, and machining for screw-in studs and guideplates. Assembled versions come ready to install with stainless steel valves, valve springs, and a complete valvetrain hardware kit including seals, locks, and retainers — sold in pairs.

For builders targeting 800+ horsepower, Speedmaster also offers 15-degree head designs with room for oversized 2.180"–2.200" intake valves, while CNC-ported heads are precision-machined on dedicated 4-axis and 5-axis CNC machining centers for consistent, repeatable port geometry.

Wide Engine Coverage

One of Speedmaster's biggest strengths in this category is its broad application coverage. Their cylinder heads span the most popular American V8 families, including:

• Chevrolet: Small Block Gen I (302, 327, 350), Big Block Mark IV / Gen V / Gen VI, and GM LS1/LS2/LS6/LS7 platforms
• Ford: Small Block Windsor (289/302/351W), 351 Cleveland, 351M, and Big Block 429/460
• Mopar: LA Small Block (318–360) and B/RB Big Block

Camshaft compatibility options — hydraulic flat tappet, solid flat tappet, hydraulic roller, and solid roller — are available across most applications, giving builders the flexibility to match heads to their intended cam profile without compromise.

Who Are Speedmaster Cylinder Heads Built For?

Speedmaster's cylinder heads occupy a smart position in the market: they deliver construction quality features typically associated with higher-priced brands — gravity die-casting, CNC-finished surfaces, bronze guides — while remaining accessible to the enthusiast building a performance street engine or entry-level race motor. Whether you're refreshing a small-block Chevy, breathing new life into a Ford Windsor, or building a stout Mopar stroker, Speedmaster's lineup on the cylinder heads category page offers a well-matched solution. Explore the full Speedmaster brand catalog for complementary engine components to complete your build.