ATK LQ4 GM 365 550 HP -LB-1 Stage 1 Long Block Crate Engine

Description

Meet aggressive naturally aspirated performance targets with the ATK LQ4-LB-1 Crate Engine in Stage 1 long block trim. Displacing 365 cubic inches, this high-output 6.0L iron block engine generates 550 horsepower at 6,400 RPM and 490 lb-ft torque at 5,000 RPM. Engineered with high-flow CNC cylinder heads, it equips builders with race-grade power inside a durable block.

A precision-machined cast iron GM LQ4 block is finished with torque plates and secured with 6-bolt cross-bolted main caps. The rotating kit pairs a 4340 forged steel 3.622-inch stroke crankshaft with 6.125-inch 4340 forged H-beam rods and 10.8:1 forged aluminum pistons inside 4.005-inch bores. An internal neutral balance configuration pairs with a high-capacity steel oil pan for consistent lubrication control.

Key Features of ATK LQ4-LB-1

Bracket racers buy ATK LQ4-LB-1 crate engine packages to secure high-RPM iron-block horsepower without expensive custom machining costs. This long block package fits fourth-generation Camaros, C10 race trucks, and pro-touring muscle cars.

• CNC-ported aluminum cylinder heads move massive air charges straight to high-flow stainless steel valves.
• 2.05-inch intake and 1.60-inch exhaust valves maximize cylinder fill efficiency for fierce top-end power output.
• 0.612-inch lift hydraulic roller camshaft profiles snap valves open rapidly for instantaneous throttle response.
• 236-degree intake duration at 0.050-inch lift profiles the engine for sustained acceleration between 3,200 and 6,600 RPM.
• 1.7:1 ratio roller rocker arms stabilize valve actuation without pushrod deflection under high valvetrain stress.
• ATK LQ4-LB-1 stroker internals undergo precise electronic dynamic balance steps to reduce harmonic vibrations under load.
• Double-roller billet timing gear set locks in precise camshaft degree alignment across prolonged race weekends.
• ARP rod bolts resist tensile elongation under severe crankshaft rotational forces during hard quarter-mile launches.

Dyno Profile Valvetrain Behavior

Operating throughout a 3,200 to 6,600 RPM performance envelope, this unit yields 550 brake horsepower at 6,400 RPM with 490 lb-ft torque at 5,000 RPM. The combustion chambers require minimum 93-octane pump fuel to suppress high-heat detonation. Camshaft profiles generate 12 in-Hg manifold idle vacuum at 850 RPM. Internal oil channels sustain 45 to 65 PSI warm oil pressure.

Chassis Clearances Bellhousing Integration

The block retains standard Gen III LS transmission bolt patterns to mate with 4L80E, 4L85E, and manual transmissions. The crankshaft tail accepts standard LS zero-balance flexplates or flywheels. Side motor mount holes accept standard LS conversion brackets, clearing aftermarket crossmembers and swap headers without frame modifications.

Lubrication Protocols Application Disclaimers

Pre-pressurize the oil galleries with an external fluid tank before introducing electrical current to the starter motor circuit. Fill the crankcase with 10W-30 conventional break-in lubricant loaded with zinc and phosphorus additives. This high-compression LS engine is not designed for marine use, supercharged boost past 6 PSI, or bracket-racing nitrous systems.

• Replace the break-in motor oil and spin on a heavy-duty filter after the first 500 operating miles.
• Inspect valve spring seat pressures and check cylinder head fastener torque every 3,000 miles of operation.
• Examine timing cover seals and inspect oil pan perimeter bolts every 12 months or 12,000 miles.

Warranty Statement Physical Manifest

ATK covers this performance engine with a 12-Month factory warranty against defects in materials and craftsmanship. The secure wooden crate holds the assembled long block, CNC aluminum cylinder heads, timing cover, oil pan, valve covers, instruction manual, and official dynamometer verification sheet.