ATK Chevy LQ9 Gen IV 408 Boost/Nitrous Short Block 24 Tooth -29cc Dished SP40-G4-B Engine

The ATK SP40-G4-B Chevy LQ9 Gen IV 408 Short Block is the heart of nitrous-boosted engines. It contains fully forged and balanced components for impeccable and superior performance. This short block has upgraded ARP main studs, rod bolts, and Total Seal piston ring package that are perfectly gapped for 10+ PSI.

Engine Specifications:

• Block: GM 6.0L Iron Gen IV
  
• Bore/Stroke: 4.030 x 4.000
  
• Displacement: 408 C.I.D.
  
• Crankshaft: Manley 4340 Forged 4.000" Stroker Internally Balanced 24 Tooth
  
• Connecting Rods: Manley 4340 Forged H Beam 6.125" ARP 2000 Bolts
  
• Pistons: Manley 2618 Forged -29cc Dished
  
• Piston Rings: Total Seal CS AP with Steel top ring gapped for nitrous/boost
  
• Compression Ratio: 64cc = 9.3:1 / 68cc = 9:1 / 72cc= 8.7:1 (can vary due to deck height/gasket thickness)
  
• Camshaft Bearings: Installed & Clocked to OEM Position
  
• Freeze Plugs: Brass Installed & Sealed
  
• Oil Galley Plugs: Installed & Sealed
  
• Weight: 285
  

Every great build needs a solid foundation! For that reason, we take the hard work out of the picture by selling short blocks that are ready for you to complete yourself. Our GM Short Blocks are most commonly packaged as the engine block assembled with Pistons, Piston Rings and Crankshaft installed.

ATK specializes in muscle. With the highest quality internal parts and Dyno Proven combinations of every engine built, ATK is able to add the most bang for your buck and back it up with an industry leading warranty.

Don't forget the engine paint!