ATK Chevy LS 408 Boost/Nitrous Short Block 58 Tooth -18cc Dished SP31-B Engine

The ATK SP31-B Chevy LS 408 Short Block is built for engines that will run with boost or nitrous. Featuring GM Iron LQ4 block, this short block is assembled with Manley forged crankshaft, Manley forged pistons and Manley forged H beam connecting rods for exceptional sturdiness and durability. Both freeze plugs and oil galley plugs come installed and sealed for trouble-free operation.

Short Block Specification

• Block: GM 6.0L Iron LQ4
  
• Bore/Stroke: 4.030 x 4.000
  
• Displacement: 408 C.I.D.
  
• Crankshaft: Manley 4340 Forged 4.000" Stroker Internally Balanced 58 Tooth
  
• Connecting Rods: Manley 4340 Forged H Beam 6.125" ARP 2000 Bolts
  
• Pistons: Manley 2618 Forged +18cc Dished
  
• Piston Rings: Total Seal CS AP Steel Top Ring
  
• Compression Ratio: 64cc=10.2:1/66cc=10.0:1/70cc=9.6:1
  
• 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!