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PSLS4271CT - LS3 427 Drop-In Performance Engine 625 HP / 565 TQ

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Pricing: $9,045.00

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625 HP/565 TQ

Drop-in LS3 Replacement engine that pumps out 625 horsepower and 565 lb-ft of torque. This configuration makes use of your existing fuel injection system, ignition, oil pan, valve covers and harmonic balancer. BluePrint Engines will even reprogram your ECM to handle the new fuel and ignition mapping.

The new engine comes with 11:1 compression ratio GM Gen III LS-series block and heads with BluePrint's forged crank and rods balanced within 2 grams, timing cover and intake manifold. Plus, each LS engine is covered by our industry-leading 30-month, 50,000-mile international warranty.

Includes intake manifold, timing cover, valley cover and rear cover.

Engine Block

  • New GM LS3/L92 Aluminum Block!
  • 1-piece rear main seal

Rotating Assembly

  • Forged Steel Crank: 4.125" stroke
  • Forged 6.125" Rods
  • Forged Mahle Pistons
  • Mahle Performance Rings
  • Roller Cam
  • Crankshaft: BluePrint or Scat with 6 Bolt Flange with Keyway for ATI or other aftermarket Balancers
  • ARP Connecting rod bolts
  • Balanced Rotating Assembly

Cylinder Heads

  • GM L92/LS3 Cylinder Heads
  • HD Roller trunion rocker arms
  • Chrome moly retainers and spring locators
  • Upgraded Dual coil .650" lift valve springs
  • 2.165 intake valves
  • 1.590 exhaust valves
  • Hardened push rods

Critical Specs

  • Performance Hydraulic Roller Cam
    • .624 intake / .624 exhaust lift;
    • 239 intake / 255 exhaust duration
    • @ .050, 114 degree lobe sep
  • Compression Ratio: 11:1
  • Fuel Requirements: 91 octane

Ignition Timing

  • ECM Controlled (not included – customer sends their original ECM to BluePrint for reprogramming


  • This engine requires a non-weighted harmonic balancer, and non-weighted flexplate/flywheel.
  • Recommended Fuel: 91 Octane
  • BluePrint Engines recommends a 2200+ RPM stall converter.
  • Engine Includes a Timing cover and LS3 Intake Manifold


  • 30 month / 50,000 mile

Application List


Shipping Information

  • Item Requires Shipping
  • 500.0 lbs.
  • W5.0000” x H5.0000” x L5.0000”
  • Free Shipping!
  • FREE 48 State Truck Freight Shipping (International shipping will require freight quote)

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