ATK LS3 415CI 620HP Base LS02 Engine

Item #22666

Made in the USA
ATK LS3 415CI 620HP Base LS02 Engine
ATK LS02 LS3 415CI 620HP Base
* ** THIS ITEM IS TEMPORARILY OUT OF STOCK *** FREE SHIPPING on ATK Engines. This item ships directly from the manufacturer and is not available for store pickup. Some engines are made-to-order or can be backordered. Delivery can be delayed up to 5 to 6 weeks but typically ship within 2 weeks.
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Creating massive horsepower of 620+, the ATK LS02 LS3 415CI 620HP Base Engine can generate huge mid to upper end power with a noticeable idle. This engine is built with aluminum cylinder heads and forged internal components and sealed oil galley plugs for enhanced performance and durability.

Engine Specifications:

  • Horsepower: 620+
  • Torque: 550+
  • Block: New GM LS3
  • Bore/Stroke: 4.065 x 4.000
  • Year Range: 2008-2017
  • Displacement: 415CI
  • Crankshaft: Manley 4340 Forged Internally Balanced 58 Tooth
  • Connecting Rods: Manley 6.125" Forged H Beams with ARP 8740 Bolts
  • Pistons: Manley 2618 Forged
  • Piston Rings: Moly Rings
  • Compression Ratio: 10.3:1 Compression
  • Camshaft: Hydraulic Roller
  • Camshaft Specifications: 240/256 @50 .625/.625 113LSA
  • Camshaft Bearings: Installed & Clocked to OEM Position
  • Cylinder Heads: New LS3 Aluminum 68cc/260cc 2.16/1.59
  • Rocker Arms: OE Rocker Arms with trunion upgrade
  • Oil Galley Plugs: Installed & Sealed
  • Weight: 412

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!
Engine Paint


ATK High Performance GM 415 LS3 Stroker 620 HP Stage 1 Long Block Crate Engines


Engine Information:

• Oil: 5W30
• Oil Filter: Wix or K&N Recommended Per Your Application
• Fuel Delivery: OE EFI System With Tune or Carb
• Intake Manifold: Factory LS3
• Fuel Injectors: 36lb for optimal Performance
• Spark Plugs: NGK #3186
• Spark Plug Gap: .035"
• Harmonic Balancer/Damper: Stock Factory Balancer Internally Balanced
• Flex Plate / Flywheel: Stock Internally Balanced
• Tuning: Needs Tune/Preferably Chassis Dyno Tune
• Timing: Set To Factory Specifications Via PCM Module (Tune Required)
• Water Pump: Per Application
• Firing Order: 1 8 7 2 6 5 4 3
• Exhaust: 1 7/8 Headers
• Fuel Pump: Upgraded
• Fuel: 91+ Octane
• Ignition: Coil Packs
• Automatic Transmission Stall Converter: 2500+


Recommended Components:

• Balancer: Stock internal balance/per application
• Carburetor: Quick Fuel 850cfm mechanical secondary's #793-Q-850
• Intake Manifold: Edelbrock Victor Jr. #350-28457
• Flexplate/Flywheel: Stock internal balance
• Fuel Pump: Electric
• Oil Pump: Melling standard volume, high pressure
• Spark Plugs: Autolite #417-104
• Spark Plug Wires: MSD #121-5574
• Timing Control: MSD #121-6014 with baseline of 10deg @0rpm, 20deg @ 500 rpm, 26deg @ 1500rpm, and 31deg at 2500-6500rpm
• Water Pump: Per application

Disclaimer: The parts listed are ATK’s recommendations of parts to be used to obtain our power figures listed. Power figures can vary based on parts used by the end user. It is the customer’s responsibility to verify components will work for their application. Some modifications to the vehicle may be required using these and or other aftermarket parts.

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