ATK LS3 GM 415 Stroker 620 HP LS02C Stage 3 Carbureted Crate Engine

Description

Featuring 415 cubic inches of displacement, the ATK LS02C Crate Engine outputs 620 horsepower at 6,300 RPM in Stage 3 complete trim. Pumping out 550 lb-ft torque at 4,900 RPM, this turn-key all-aluminum power plant includes a four-barrel carburetor, intake, ignition, and water pump. It furnishes pro-touring builds with tire-smoking big-inch authority straight from the freight pallet.

A lightweight aluminum GM LS3 block forms the rigid structural foundation, equipped with 6-bolt cross-bolted main caps. The internally balanced rotating kit features a 4340 forged steel 4.000-inch stroke crankshaft, 4340 forged H-beam rods, and 10.7:1 forged pistons inside 4.070-inch bores. An internal neutral balance configuration joins an oil-baffled pan for total crankcase fluid control under extreme g-forces.

Key Features of ATK LS02C

Discerning vehicle builders buy ATK LS02C crate engine products to bypass EFI tuning complications while obtaining dyno-proven 620-horsepower performance. This complete package repowers vintage muscle cars, Pro-Touring coupes, and high-end street rods.

• 850 CFM dual-feed four-barrel carburetor discharges calibrated fuel mixtures straight out of the secure shipping crate.
• Single-plane aluminum intake manifold flows balanced fuel charges into rectangular intake ports past 6,500 RPM.
• CNC-ported aluminum cylinder heads maximize airflow volume to feed large 4.070-inch cylinder bores.
• 0.620-inch lift hydraulic roller camshaft delivers aggressive valve lift curves without requiring constant solid-lifter adjustments.
• 238-degree intake duration at 0.050-inch lift profiles the powerband for massive pulling force off launching lines.
• 1.7:1 ratio roller rocker arms stabilize valve actuation without pushrod deflection under high valvetrain stress.
• ATK LS02C complete power packages include an electronic ignition controller that programs timing curves without a computer.
• High-flow water pump circulates coolant through internal block jackets to shed excess operating heat under track conditions.

Combustion Dyno Performance Metrics

Dyno testing validates 620 brake horsepower at 6,300 RPM backed by 550 lb-ft torque at 4,900 RPM across a 3,000 to 6,600 RPM band. High compression demands 93-octane premium service-station gasoline. Manifold vacuum settles at 11 in-Hg at an 850 RPM idle setting. Internal oil pump pressure regulates firmly between 45 and 65 PSI under load.

Frame Envelope Transmission Connections

Exterior dimensions mirror standard Chevrolet LS3 dimensions, dropping between frame rails in vintage A-body, F-body, and C10 chassis. The internally balanced crank tail accepts standard zero-balance flexplates or flywheels for 4L80E or manual gearboxes. Engine mount locations fit standard LS conversion brackets, leaving generous space for tubular exhaust headers and steering linkages.

Start Protocols Operation Boundaries

Pre-lube the engine with a dedicated mechanical tool before turning the ignition key to ensure complete bearing lubrication. Fill the crankcase with 10W-30 conventional break-in lubricant loaded with zinc and phosphorus additives. This turn-key engine is not designed for salt water marine use, supercharged boost past 6 PSI, or bracket-racing nitrous systems.

• Drain break-in motor oil and spin on a new filter canister after the first 500 operating miles.
• Inspect carburetor throttle linkage, fuel line fittings, and baseplate bolts every 3,000 miles of street use.
• Check ignition timing controller wiring, grounds, and spark plug boots every 12 months or 12,000 miles.

Warranty Information Package Inventory

ATK protects this package with a 12-Month factory warranty against defects in materials and manufacturing. The wooden shipping container holds the fully dressed engine, carburetor, intake manifold, ignition controller, water pump, harmonic balancer, oil pan, valve covers, and official dynamometer test sheet.