ATK Ford 347 Stroker 410 HP HP20 Stage 1 Long Block

ATK Ford 347 Stroker – Windsor Street-Strip Application

The ATK Ford 347 Stroker 410 HP HP20 Stage 1 Long Block eliminates the low-end torque bottleneck inherent in standard displacement 302ci Windsor builds. By expanding volume to 5.7L, this Stage 1 unit solves the volumetric efficiency gaps found in stock 5.0L blocks. The added mechanical leverage spools the power band faster, preventing destructive cylinder wall heat-soak through high-flow aluminum cylinder head architecture designed for aggressive street performance.

Integrating this professionally blueprinted long block architecture provides a massive ROI by removing the variable costs of local machine work and parts matching. Selecting this HP20 package saves roughly 54 hours of shop labor through its pre-cleared stroker rotating assembly and hydraulic roller setup. This dyno-ready foundation ensures 410 HP consistency, offering shop owners a dependable 347ci solution that significantly reduces the threat of component fatigue during initial tuning.

ATK High Performance HP20 Engineering Specifications

• The reciprocating assembly features a 347 cubic inch stroker displacement profile
• Peak performance reaches 410 HP output with high torque capacity
• Internal compression is set at Stage 1 ratios for thermal efficiency
• Rotating components consist of high-tensile materials to maintain stability
• Cylinder head architecture utilizes aluminum for superior heat dissipation
• The block foundation uses cast iron to prevent cylinder wall distortion
• Valvetrain configuration follows hydraulic roller standards to ensure timing control

Ford 347 Stroker Power & BMEP Characteristics

The 347 cubic inch stroke anchors the torque peak in a broader RPM window than traditional 302 builds. This modification improves the instantaneous throttle response sensitivity, making the platform highly responsive for classic Mustang or Bronco swaps. Under hydraulic roller control, the BMEP remains stable, preventing detonation during rapid acceleration events in high-performance environments while maintaining linear power delivery.

Material Integrity & Ford Windsor Durability

Durability is engineered through the combination of a high-rigidity iron block and lightweight aluminum heads. This hybrid construction eliminates thermal fatigue risks common in all-iron configurations when subjected to high-load cycles. The external 28 oz. balancing process removes stress risers from the crankshaft, ensuring survival through extreme heat cycles typical of high-performance Ford muscle car restorations.

HP20 Drivetrain & Ford Windsor Integration

This engine bolts directly to Ford transmissions utilizing a 1-piece rear main seal and Windsor bolt patterns. Because the assembly uses a 28 oz. external imbalance, builders must ensure the included harmonic balancer is matched with a 28 oz. flexplate. This prevents destructive torsional vibrations that could damage sensitive drivetrain bearings or the transmission input shaft during high-RPM street-strip operations.

Ford 347 Stroker Street & Swap Versatility

This 347ci unit is a primary choice for Mustang restorations, Fox-body upgrades, and classic F-100 truck conversions. It maintains a safe compression safety margin, allowing for worry-free operation on standard 91 octane pump fuel. The hydraulic roller valvetrain ensures smooth idle quality and AFR stability, making 410 HP manageable in heavy traffic or during long-distance highway cruising.

Fitment & Ford 347 Stroker Installation Protocol

Builders must confirm chassis clearance for the provided oil pan and aluminum head width. The protocol demands verifying the fuel pump flow to support the 410 HP peak output potential. Check accessory drive alignment against the provided timing cover and valve covers. Professional priming of the lubrication system is mandatory before the first Windsor ignition to ensure bearing longevity.

Warranty & Support Compliance

ATK High Performance stands behind this 5.7L build with a limited **12-month warranty** against defects in workmanship. Claims require valid proof of professional installation and a completed warranty registration form. US-based tech support provides startup and break-in guidance to safeguard this significant mechanical investment during the critical first 500 miles of operation.

Final installation and chassis compatibility must be verified against manufacturer’s current technical bulletin and vehicle-specific measurements.