ATK Engines High-Performance Short Block GM LS 408ci
059-SP39-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
NOTE:
- Core return can be any Chevy LS 6.0L engine
This short block is built for engines that are going to be running boost or nitrous. It has upgraded ARP main studs, rod bolts, and Total Seal piston ring package gapped accordingly for 10+ PSI.
Block Information:
- Seasoned OE 2001-2007 GM Cast Iron LQ4 6.0L with ARP main studs
- Bore/Stroke: 4.030" x 4.000"
- Displacement: 408ci
- Camshaft Bearings: Installed and clocked to OEM position
- Freeze Plugs: Installed and sealed
- Oil Galley Plugs: Installed and sealed
Rotating Assembly:
- Crankshaft: Manley 4340 forged 24-tooth reluctor wheel
- Rods: Manley 4340 forged H beam rods with ARP 2000 bolts
- Compression Ratio: 64cc= 11.9:1 68cc= 11.4:1 / 72cc= 11.0:1
- Pistons: Manley 2618 flat top +4cc
- Rings: Total Seal CS AP with steel top rings gapped for boost/nitrous
Recommended Components:
- Balancer: Internal balance
- Flexplate/Flywheel: Internal balance
- Head Gasket: .051" thickness or per application
- Oil: 10W40 Non synthetic for first 3000 miles
- Oil Filter: Wix or K&N per application
- Oil Pump: Melling #689-10295 with high pressure spring
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:
How much Boost can it hold?
Will there be any issues running this in an N/A condition? I am considering this short block over the same non-nitrous/boost ready one (SP-39) due to this one having ARP mains already installed. No plans for nitrous or boost.
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