ATK HP42C 540 Crate Engine – 660 HP Big Block Chevy

The Ultimate 540 BBC Crate Engine for Maximum Performance

The ATK HP42C 540 crate engine delivers massive horsepower and torque in a complete Stage 3 package that’s ready to drop into your classic Chevelle, Camaro, hot rod, or custom build. As part of our extensive Big Block Chevy collection, this 8.8L/540 cubic inch V8 produces a staggering 660 horsepower and 650+ lb-ft of torque—making it one of the most formidable naturally aspirated big-block crate engines in ATK’s Stage 3 lineup .

Built on a Dart Big M cast iron block with a Manley 4340 forged steel crankshaft and forged pistons, this 540 Pro Series engine is dyno-tested and backed by a 2-year/unlimited mileage warranty . Whether you’re building a weekend warrior, a drag-race monster, or a show-stopping hot rod, this ATK 540 crate engine provides the foundation for an unforgettable driving experience.

What Makes the ATK 540 Stage 3 the Ultimate BBC Crate Engine?

The HP42C is engineered for enthusiasts who want maximum horsepower and torque with complete turn-key convenience. ATK has been building engines for over 75 years and has assembled this dyno-proven crate engine package to power up your ride . This Stage 3 Complete variant includes a Dart Big M block, high-performance aluminum cylinder heads, intake manifold, carburetion, distributor, plug wires, spark plugs, valve covers, timing cover and timing set, oil pan, pump, and pickup tube, water pump, and front damper and flexplate—making it a true turn-key solution .

540 Crate Engine Horsepower and Torque Figures

This big-block crate engine produces staggering output that puts most performance engines to shame:

• 660 horsepower – dyno tested and verified 

• 650+ lb-ft torque – massive big-block torque for street and strip 

• 10.0-10.1:1 compression ratio – pump gas friendly 

• Hydraulic roller cam – streetable performance with excellent durability 

Complete 540 Stage 3 Engine Specifications

Dart Big M Cast Iron Block

The foundation of this ATK 540 crate engine is the legendary Dart Big M cast iron block, featuring :

• 4-bolt main caps for exceptional bottom-end strength

• 2-piece rear main seal – traditional BBC design 

• 4.500-inch bore x 4.250-inch stroke (540 CID / 8.8L) 

• 9.8-inch deck height 

• Internal engine balance 

Forged Rotating Assembly

The rotating assembly in the HP42C is built for durability and high horsepower :

• Manley 4340 forged crankshaft – 4.250-inch stroke, internally balanced 

• Manley 4340 forged H-beam connecting rods – 6.385″ length with ARP 8740 bolts 

• Forged pistons – 10.0-10.1:1 compression 

• Moly piston rings for superior sealing 

Dart Aluminum Cylinder Heads

The Dart Pro 1 aluminum cylinder heads provide exceptional flow :

Pro Series Hydraulic Roller Camshaft Specifications

The HP42C features a custom hydraulic roller camshaft :

What’s Included with Your HP42C Stage 3 Crate Engine

The HP42C comes as a complete Stage 3 dressed long block with the following components included :

Important Note: This is a complete, dyno-tested engine package. ATK recommends the following components for optimal performance: Holley 130GPH mechanical fuel pump, 91+ octane fuel, 3000+ RPM stall converter for automatic transmission, and 2-1/8″ headers .

Installation Notes and Critical Considerations

Important Notes Before Installation

Before installing your ATK HP42C crate engine, review these critical notes :

• Not for use in pollution-controlled vehicles 

• Designed for street/strip applications – will have a rough idle, power brakes will not work 

• Requires 91+ octane fuel 

• 36 degrees total timing recommended 

• Max RPM: 5,800 

• Firing order: 1-8-4-3-6-5-7-2 

• Recommended oil: 10W30 with zinc additive during break-in 

• Spark plug gap: .035″ 

Exhaust and Fuel Requirements

• Headers: 2-1/8″ primary tubes recommended 

• Fuel Pump: Holley 130GPH mechanical 

Emissions Compliance

Important: This product is not for use in pollution-controlled vehicles. Computer-controlled vehicles may need updated chips or other modifications . It is designed for pre-1976 street vehicles, off-road applications, or competition use only.

Break-In Recommendations

ATK recommends the following break-in procedure :

• Use break-in oil or conventional (non-synthetic) 10W30 oil with zinc additive for the first 500 miles

• Do not drive for long periods at any single speed – vary your speed

• Do not tow a trailer or put heavy loads on the vehicle during break-in

• Check engine oil and coolant levels daily

• At 500 miles, change oil and filter using conventional (non-synthetic) oil with zinc additive

• Change oil again at 1,000 miles

• After 4,000 miles, you may run quality 10W30 synthetic oil

Warranty

ATK High Performance backs the HP42C with a 2-year / unlimited mileage warranty .

ATK HP42C Engine FAQs

What is the horsepower and torque of the HP42C?

The ATK HP42C produces 660 horsepower and 650+ lb-ft of torque .

What’s included with the HP42C?

The HP42C is a complete Stage 3 dressed engine including the Dart Big M block, aluminum cylinder heads, forged rotating assembly, intake manifold, carburetor, distributor, water pump, harmonic balancer, flexplate, oil pan, valve covers, timing cover, spark plugs, and wires .

What is the displacement and configuration of this engine?

The HP42C is a 540 cubic inch (8.8L) Big Block Chevy V8 with a 4.500-inch bore and 4.250-inch stroke. It features a Dart Big M cast iron block with aluminum heads and a 10.0-10.1:1 compression ratio .

What fuel does the 540 require?

91+ octane fuel is recommended for optimal performance .

What is the warranty on the HP42C?

ATK High Performance backs the HP42C with a 2-year / unlimited mileage warranty .

What is the price of the HP42C?

The HP42C is priced at approximately $14,710 – $14,998 . Contact NH Race Engine for current European pricing and availability.

What certifications does ATK hold?

All of ATK’s manufacturing facilities have achieved both QS-9000 and ISO 9001 certification levels, one of the few engine remanufacturers in the world to have done so .