LS7 427CI 625HP Airboat Engine Fuel Injected

Starting at Call For Pricing

If your are in the market for a lightweight engine to re-power your airboat with high horsepower and torque, our Gen IV engine is what you need. Proformance Unlimited’s LS 427 airboat engine was designed with the airboater in mind. Reliability and fuel economy while still producing the power that is needed for all types of environmental conditions. We back up all our complete airboat engines with a 1 year unlimited hour warranty for your peace of mind. This engine combination comes complete with a marine grade ECM, wiring harness and sensors. We here at Proformance Unlimited have years of designing and building engines that last the test of time. Feel free to give us a call with any questions you have.


625 @ 6300


580 @ 5300

Bore & Stroke

4.125 - 4.000

  • GM LSX Iron 6 Bolt Main Block
  • Eagle 4340 forged steel crankshaft 4.125 stroke
  • Eagle H-Beam connecting rods with ARP bolts
  • High performance pistons (SRP, or Mahle) 4.070 bore
  • Performance rods and main bearing (Clevite, King or Federal Mogul)
  • Performance rings hand filed to match application
  • Rotating assembly is balanced
  • Comp Cams custom ground hydraulic roller camshaft
  • Hydraulic roller lifters
  • Three piece roller timing set
  • GM Performance aluminum cylinder heads
  • Comp Cams Screw in studs and hardened guide plates
  • Manley chrome moly push rods
  • Performance roller rockers
  • Melling high volume oil pump
  • Milodon oil pan
  • Milodon dipstick and tube
  • Aluminum timing cover
  • Performance balancer
  • Fel-Pro gaskets
  • Holley intake manifold
  • Holley throttle body
  • Holley fuel injection system computer, sensors, harness
  • Fuel Injectors
  • Thermostat housing
  • Performance coil packs
  • Auto-Lite spark plugs
  • Custom fit Taylor ignition wires
  • Water pump
  • Valve covers
  • Water flow redirection fitting and hose
  • Engines are photo documented during the building process
  • Each engine is dyno tested, timing set and fuel injection adjusted for optimum performance
  • We video tape your engine and send you a copy
  • 2 Year 250 Hour Marine Warranty

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