Building a 347 stroker is a popular way to get big displacement from a small-block Ford 302. But with so many kits on the market, choosing the right one is critical for reliability and power. We researched and compared seven of the best 347 stroker kits, evaluating manufacturer specifications, published industry standards, and aggregated owner feedback. This guide will help you make an informed decision based on your goals and budget.
| Photo | Product | Score | Buy |
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Ford Racing M-6007-X347 Top Pick Complete rotating assembly: forged pistons, H-beam rods, 4340 crank |
9.2 | 🛒 Check Price |
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Eagle 347 Stroker Kit Best Value 4340 forged crank, I-beam rods, hypereutectic pistons |
8.7 | 🛒 Check Price |
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Scat 1-94140-347 Best for High HP 4340 forged crank, H-beam rods, forged pistons |
9.0 | 🛒 Check Price |
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Speedmaster PCE261.347 Budget Friendly Cast crank, I-beam rods, hypereutectic pistons |
7.8 | 🛒 Check Price |
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Proform 141-347 Balanced Assembly Forged crank, H-beam rods, forged pistons, pre-balanced |
8.1 | 🛒 Check Price |
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ATK HP2S347 Long Block Option Complete long block: assembled with heads and valvetrain |
8.4 | 🛒 Check Price |
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Blueprint Engines BPS347 Turnkey Solution Complete turnkey engine: dressed with accessories |
7.3 | 🛒 Check Price |
1. Ford Racing M-6007-X347: Top Pick
The Ford Racing M-6007-X347 is a complete rotating assembly engineered specifically for 5.0L Ford blocks. It includes forged pistons, H-beam connecting rods, and a 4340 steel crankshaft, all pre-balanced for minimal vibration. In our evaluation, owner feedback consistently praises its drop-in fitment and long-term durability. The kit meets OEM tolerances, making it a top choice for those seeking a reliable stroker without guesswork.
However, this kit carries a premium cost that may not be justified for budget-conscious builders. It also requires a compatible block and may need clearancing on some early blocks. If you’re building a high-horsepower engine on a tight budget, a more affordable kit might be a better fit.
- Factory-engineered by Ford Performance for drop-in reliability
- Includes forged pistons, H-beam rods, and 4340 steel crankshaft
- Balanced assembly reduces vibration and extends engine life
Pros: Excellent build quality and fitment; Comes fully balanced and ready to install
Cons: Premium price point may not suit budget builds
2. Eagle 347 Stroker Kit: Best Value
The Eagle 347 Stroker Kit provides a solid foundation for a street performance build. It features a 4340 forged crankshaft, I-beam rods, and hypereutectic pistons. Based on owner feedback, this kit delivers reliable power gains when paired with proper cylinder heads and camshaft. The included bearings simplify the assembly process.
One limitation is the use of I-beam rods, which are heavier than H-beam rods and may not be ideal for sustained high-RPM use. If you plan to spin the engine past 6500 RPM regularly, consider upgrading to an H-beam rod kit. For most street applications, however, this kit offers excellent value.
- 4340 forged steel crankshaft for strength
- Hypereutectic pistons offer good thermal stability
- Includes rod and main bearings
Pros: Great balance of price and performance; Includes all necessary bearings
Cons: I-beam rods are heavier than H-beam alternatives
3. Scat 1-94140-347: Best for High HP
The Scat 1-94140-347 is a robust rotating assembly built for high-output applications. It features a 4340 forged crankshaft, H-beam rods, and forged pistons with coated skirts. In our research, this kit is frequently recommended for forced induction builds due to its strength. Owner feedback highlights its ability to handle extreme power levels without failure.
Installation can be more involved, as the larger rod journals may require block clearancing. This kit is not a simple drop-in for all engines. If you are not experienced with engine building or prefer a straightforward install, consider a kit with smaller journals.
- 4340 forged steel crank with large journal option
- H-beam rods withstand high horsepower and RPM
- Forged pistons with coated skirts reduce friction
Pros: Handles up to 600+ horsepower reliably; High-quality forging process
Cons: Requires careful clearancing on some blocks
4. Speedmaster PCE261.347: Budget Friendly
The Speedmaster PCE261.347 is a budget-oriented kit that includes a cast iron crankshaft, I-beam rods, and hypereutectic pistons. It also comes with a gasket set and bearings, making it a convenient all-in-one package. Based on owner feedback, it works well for mild street builds aiming for around 300-350 horsepower.
However, the cast crank is not designed for high stress. If you plan to rev past 6000 RPM or add forced induction, this kit will likely fail. It is best suited for a low-budget cruiser or first-time builder who accepts the limitations.
- Affordable entry into 347 displacement
- Cast iron crankshaft for street use
- Includes gasket set and bearings
Pros: Very low cost for a complete kit; Includes gaskets and bearings
Cons: Cast crank limits power potential; Not suitable for high-RPM or boost
5. Proform 141-347: Balanced Assembly
The Proform 141-347 is a pre-balanced rotating assembly featuring a forged 4340 crankshaft, H-beam rods, and forged pistons. The kit aims to reduce installation complexity by arriving balanced. In our evaluation, many owners found it a convenient upgrade for street/strip use, with smooth operation at moderate RPM.
However, a few owner reviews mention that the balance was not perfect and required rebalancing. This adds unexpected cost and hassle. If you want guaranteed precision, you might prefer a kit from a brand with tighter quality control.
- Pre-balanced rotating assembly for smooth operation
- Forged 4340 crank and H-beam rods
- Forged pistons with wire rings
Pros: Comes balanced, saving machine shop costs; Good component quality for the price
Cons: Some users report minor balance issues out of box
6. ATK HP2S347: Long Block Option
The ATK HP2S347 is a complete long block engine, not just a rotating assembly. It comes fully assembled with aluminum cylinder heads, a hydraulic roller camshaft, and valvetrain. Based on owner feedback, it provides a hassle-free path to a 347 stroker with proven dyno numbers.
The main drawback is the higher cost compared to short block or rotating assembly kits. Additionally, the included components may not match your specific goals (e.g., cam profile). If you prefer to choose your own cylinder heads and cam, a short block kit is more flexible.
- Fully assembled long block with aluminum heads
- Includes hydraulic roller cam and lifters
- Dyno tested before shipping
Pros: Ready to install out of the crate; Includes high-quality aluminum cylinder heads
Cons: More expensive than short block kits; Heavier to ship and handle
7. Blueprint Engines BPS347: Turnkey Solution
The Blueprint Engines BPS347 is a turnkey 347 stroker engine that comes fully dressed with an intake manifold, carburetor, distributor, and all necessary accessories. It is designed for a simple swap into classic Ford vehicles. Owner feedback often praises the convenience: just install and start.
However, the components are entry-level, and the engine may not satisfy experienced builders seeking high performance. The included carburetor and intake are basic, and the camshaft is mild. If you want a custom build with premium parts, this kit is not for you. It is best for a straightforward, reliable daily driver.
- Fully dressed engine with intake, carb, and distributor
- Includes water pump, harmonic balancer, and flexplate
- Dyno tested and ready to run
Pros: Everything included for a drop-in installation; Good for beginners with no engine building experience
Cons: Lower quality components than custom builds; Limited upgrade potential without replacing parts
Frequently Asked Questions
What is a 347 stroker kit?
A 347 stroker kit replaces the crankshaft, connecting rods, and pistons in a Ford 5.0L (302) small-block engine to increase displacement to 347 cubic inches. This is achieved by using a longer stroke crankshaft (3.400 inches) and appropriate pistons. The kit typically includes a rotating assembly and sometimes bearings and gaskets.
Will a 347 stroker kit fit my Ford 302?
Most 347 stroker kits are designed for the 5.0L Ford small-block (302) with a 28 oz imbalance. However, block variations (e.g., 5.0L roller cam vs. earlier 302) may require clearancing for the larger crankshaft counterweights. Always check compatibility with your specific block casting number before purchasing.
What horsepower can I expect from a 347 stroker?
Horsepower depends on cylinder heads, camshaft, induction, and tuning. A typical street 347 with iron heads and a mild cam can produce 300-350 hp. With aluminum heads, a performance cam, and good intake/exhaust, 400-450 hp is common. Forced induction builds can exceed 600 hp with proper components.
Do I need to balance a stroker kit?
Many kits come pre-balanced from the manufacturer, but it is recommended to have the rotating assembly balanced by a machine shop to ensure optimal smoothness and longevity. Even pre-balanced kits can have slight variations due to manufacturing tolerances.
What other parts do I need for a 347 build?
In addition to the rotating assembly, you will need cylinder heads, camshaft, lifters, timing set, oil pump, gaskets, and a harmonic balancer. For a complete engine, also include an intake manifold, carburetor or fuel injection, distributor, and exhaust headers. A proper tune is essential.
Our Verdict
After extensive research and comparison, our top pick is the Ford Racing M-6007-X347 for its factory engineering and reliability. For those seeking the best value, the Eagle 347 Stroker Kit offers a great balance of performance and cost. Choose based on your horsepower goals and budget.
