ATK Engines High Performance Short Block GM LS 408ci
059-SP40-G4-B
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LS Gen III/IV
ATK Core Return Process
JEGS and ATK appreciate your business and want to ensure that your core return is as smooth as possible.
Please CLICK HERE for ATK Core Return Process
- Core return can be any Chevy LS 6.0L engine
Engine Specifications:
- Block: Seasoned 6.0L Iron Gen IV with ARP main studs
- Bore/Stroke: 4.030” x 4.000”
- Displacement (cu.in): 408
- Crankshaft: Manley 4340 forged 24 tooth reluctor wheel
- Rods: Manley 4340 forged H beam 6.125” ARP 2000 bolts
- Pistons: Manley 2618 forged -29cc dished moly skirt coated
- Rings: Total Seal CS AP with steel top rings gapped for boost/nitrous
- Compression Ratios: 64cc = 9.3:1 / 68cc = 9.0:1 / 72cc = 8.7:1 (can vary due to deck height/gasket thickness)
- Camshaft Bearings: Installed & Clocked to OEM Position
- Freeze Plugs: Installed & Sealed
- Oil Galley Plugs: Installed & Sealed
Recommended Components:
- Balancer- Internal balance
- Flexplate/ Flywheel- Internal balance
- Head Gasket: .051” or per application
- Oil Pump: Melling #10295 with high-pressure spring
Engine Info:
- Oil: 10W40 Non-synthetic for first 3000 miles
- Oil Filter: Wix or K&N per application
Notes: ATK’s Boost/Nitrous short blocks are meant for engines running these setups. Bearing clearances and ring gap have been taken into consideration for this series of short blocks.
Specifications:
Motor Vehicles
WARNING: Motor vehicles contain fuel, oils and fluids, battery posts, terminals and related accessories which contain lead and lead compounds and other chemicals known to the State of California to cause cancer, birth defects and other reproductive harm. These chemicals are found in vehicles, vehicle parts and accessories, both new and as replacements. When being serviced, these vehicles generate used oil, waste fluids, grease, fumes and particulates, all known to the State of California to cause cancer, birth defects, and reproductive harm.
Tools:
WARNING: Some dust created by power sanding, sawing, grinding, drilling, and other construction activities contains chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. Some examples of these chemicals are: lead from lead-based paints, crystalline silica from bricks and cement and other masonry products, and arsenic and chromium from chemically treated lumber. Your risk from exposure to these chemicals varies, depending on how often you do this type of work. To reduce your exposure, work in a well-ventilated area and with approved safety equipment, such as dust masks that are specially designed to filter out microscopic particles.
Electrical Cords
WARNING: The wires of these products contain chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. Wash hands after handling.