ATK HP94M GM 383 Stroker 415 HP Stage 2 Aluminum Head Crate Engine

Description

Drop elapsed quarter-mile track times using the ATK HP94M Crate Engine in Stage 2 mid-dress configuration. Producing 415 horsepower at 5,300 RPM and 440 lb-ft torque at 4,000 RPM, this 383 cubic inch stroker comes with an aluminum intake, distributor, and water pump. It permits car builders to select personalized carburetors or electronic fuel injectors.

A blueprinted 4-bolt main cast iron GM block forms the foundation, finish-honed with precision torque plates. The reciprocating group consists of a 4340 forged steel 3.800-inch crankshaft, forged 5.700-inch connecting rods, and 10.0:1 hypereutectic pistons within 4.000-inch bores. An external-balance 5-quart passenger-side dipstick oil pan holds vital high-zinc engine oil during heavy street performance runs.

Key Features of ATK HP94M

Performance enthusiasts buy ATK HP94M crate engine assemblies to drop proven small-block stroker power into project cars while personalizing fuel induction components. The mid-dress configuration powers high-speed street rods, drag racers, and classic muscle cruisers.

• Dual-plane aluminum intake manifold comes pre-installed to seal cylinder head intake runners without tedious gasket alignment.
• 64cc CNC-shaped aluminum combustion chambers promote rapid flame propagation while suppressing engine detonation tendencies.
• 190cc intake runners accelerate incoming air velocity for massive mid-range acceleration and instant throttle recovery.
• 0.528-inch lift hydraulic roller camshaft reduces internal friction while sustaining broad power from 2,200 to 5,800 RPM.
• 220-degree intake duration at 0.050-inch lift ensures an aggressive muscle car exhaust cadence at idle.
• 1.5:1 ratio aluminum roller rockers minimize side loads on valve stems to stop guide wear over extended miles.
• ATK HP94M mid-dress models arrive with a cast iron water pump featuring factory small-block Chevrolet belt alignment.
• Electronic distributor provides stable ignition advance curves to burn compressed fuel charges under load.

Dyno Certification Output Spectrum

Dynamometer calibration tests verify 415 horsepower at 5,300 RPM and 440 lb-ft torque at 4,000 RPM across an effective 2,200 to 5,800 RPM range. The 10.0:1 compression ratio operates safely on 91-octane premium gasoline. Cam duration provides 14 in-Hg manifold vacuum at 850 RPM idle speeds. The internal oil system regulates warm oil pressure between 45 and 65 PSI.

Chassis Clearances Bellhousing Integration

External block dimensions match standard Chevrolet small-block profiles, clearing crossmembers and inner fender aprons in classic muscle platforms. The external-balance rear crank flange connects straight to matching GM flexplates or flywheels. Motor mount pads line up with factory GM frame stands, clearing steering linkages and large-tube headers without chassis cutouts.

Pre-Lube Protocol Service Cautions

Prime internal oil galleries using a dedicated pre-lube rod until fresh lubricant pools around every rocker arm pivot before starting. Use mineral-based 10W-30 break-in oil containing high ZDDP additives to coat bearing surfaces during initial running cycles. This power plant is not engineered for marine bilge setups, forced induction past 6 PSI, or unmetered nitrous shots.

• Replace the initial break-in oil and install a high-flow oil filter after the first 500 operating miles.
• Inspect intake manifold hold-down bolts and examine coolant hose clamps every 3,000 miles of street use.
• Check valve lash clearances and inspect harmonic balancer integrity every 12 months or 12,000 miles.

Warranty Terms Shipping Manifest

ATK covers the engine with a 12-Month limited warranty for authorized recreational and street performance vehicle applications. The reinforced crate holds the assembled engine, aluminum intake manifold, water pump, distributor, harmonic balancer, oil pan, valve covers, and engine dynamometer report.