LS9 Long Block (Built for Boost)


  • Assembly does not include any electronics
  • Includes dry-sump oil pan and requires external oil tank (not included). Oil pan change required for wet-sump oiling
  • Includes 9-bolt crankshaft flange that may require adapter for use with some transmissions
  • Induction system and front-end accessory drive system not included
  • Not intended for marine applications

Shipping is free, but there is a delivery fee for residential addresses.

SKU: 12624262 Categories: , Tag:

As the foundation for the supercharged engine that powered the 2009-13 Corvette ZR1, our LS9 is a long block built for boost—delivered without the supercharger or front-end accessory drive system, allowing the builder to finish the engine with the power adder of his or her choice. It is rated for 12 lbs. of boost. The assembly includes a forged rotating assembly (including lightweight titanium connecting rods), rotocast aluminum cylinder heads with titanium intake valves and stainless hollow exhaust valves, multiple engine sensors and six ignition coils. It also includes a dry-sump oil pan, which requires the builder to add an external oil tank.
Whether you use a supercharger or turbo system, the LS9 long block is the assembled foundation developed for the boost you want to make. It made the C6 ZR1 a legend in its own time—and there’s no telling where its performance potential will take your project!

  • Engine Type: LS-Series Gen-IV Small-Block V-8
  • Displacement (cu. in.): 376 (6.2L)
  • Bore x Stroke (in.): 4.065 x 3.622 (103.25 x 92 mm)
  • Block: Cast-aluminum with six-bolt, cross-bolted main caps
  • Crankshaft (P/N 12641693): Forged steel with nine-bolt flange
  • Connecting Rods (P/N 12624231): Forged titanium
  • Pistions (P/N 19180414): Forged alumium
  • Camshaft Type (P/N 12638427): Hydraulic roller
  • Valve Lift (in.): .562 intake / .558 exhaust
  • Cylinder Heads (P/N 12621774): Aluminum L92-style ports; “as cast” with 68-cc chambers
  • Valve Size (in.): 2.160 titanium intake / 1.590; hollow, sodium-filled exhaust
  • Compression Ratio: 9.1:1
  • Rocker Arms (P/N 12696105 int.): Investment-cast, roller trunnion
  • Rocker Arms (P/N 12681275 exh.): Investment-cast, roller trunnion
  • Rocker Arm Ratio: 1.7:1
  • Recommended Fuel: Premium pump
  • Maximum recommend rpm: 6600
  • Reluctor Wheel: 58X
  • Balanced: Internal

Consists of engine block, crankshaft, connecting rods, pistons, piston rings, cylinder head assemblies (including valve train components), lifters, camshaft, timing gears and chain, timing chain dampener, front cover, harmonic balancer, oil pump, valve covers and oil pan, unless otherwise specified.

Also includes Piston cooling oil nozzles, Engine oil cooler, 6 Ignition coils, Multiple engine sensors, Full forged rotating assembly, Titanium Intake valves, Stainless hollow exhaust valves, and is designed for boost straight from production

Weight 377 lbs
Dimensions 33 × 29.5 × 33 in

Prop65WARNING: These auto parts can expose you to chemicals including phthalates and lead. Installing or using these parts can expose you to other parts containing these chemicals and to engine exhaust, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to