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MTM117-422 - Mast Motorsports Complete LSX 440 SS (660hp), NO ECM or Harness

This product may require vehicle validation(s) for proper fitment. Please contact us to confirm correct vehicle fitment and usage.

Availability: Special Order Item
Shipping: FREE 48 State Shipping
Pricing: $16,620.95

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The X-Block 440 SS’s heart and soul is the new GM Performance LSX block. This X-Block engine family utilizes a Mast Motorsports engineered camshaft that is custom ground on a Mast Motorsports 3 bolt cam core. The 440 SS’s foundation is a fully machined X-Block block with a forged Callies rotating assembly with Mahle pistons that is topped off with Mast Motorsports CNC LS7 285 casting cylinder heads and a LS7 intake manifold. ARP fasteners are used throughout and Manley pushrods ride on GM Cadillac High RPM hydraulic roller lifters. This hand built X-Block based engine utilizes a camshaft that has a strong lope that creates great mid and high RPM power for the customer that will be aggressively racing their vehicle, but still wants great street manors for a daily driver.

Type: X-Block 7.2L
Displacement: 440 Cubic Inches
Compression Ratio: 12:1
Bore x Stroke: 4.185 x 4.000
Rev Limit: 7250 RPM
Crank: Callies Forged
Rods: Callies H-Beam
Pistons: Mahle Motorsports
Cam: Mast Custom 3-Bolt Core Cam
Heads: Mast Black Label CNC LS7 285 Heads
Intake: GMPP LS7 Intake
Valve Springs: Mast Dual .700 Lift

Engine Components:

  • LSX Iron Block
  • Plateau Honed to 4.185”
  • True Surfaced Deck
  • Engine Block Deburred
  • Blueprinted Short block
  • Clevite Rod and Crank Bearings
  • Callies Forged 4.000” Stroked Crankshaft
  • Callies Forged H-Beam Connecting Rods
  • Custom Mahle Motorsports Pistons
  • Mast Black Label LS7 285cc Heads
  • ARP Head Bolts
  • ARP Main Studs
  • Cometic Head Gaskets
  • Mast Custom Hydraulic Roller Cam
  • GM Hydraulic Roller Lifters
  • Mast Black Label Pushrods
  • Mast Dual Valve Springs
  • Mast Stainless Intake Valves
  • Mast Stainless Exhaust Valves
  • Mast Black Label Titanium Retainers
  • Mast Black Label Locks
  • LS7 Intake Manifold
  • GM 90mm DBW Throttle Body
  • Bosch Dead Headed Fuel Rail
  • Bosch LS7 Fuel Injectors
  • Crankshaft Position Sensor
  • Camshaft Position Sensor
  • Oil Pressure Sensor
  • Oil Temperature Sensor
  • Engine Coolant Temperature
  • Engine Knock Sensors
  • Manifold Air Pressure Sensor
  • Ignition Coils
  • Spark Plugs
  • Plug Wires
  • GM Starter
  • GM Oil Filter
  • Engine Break in Oil Additive
  • Choice of F-Body, Y-Body, or Truck Water Pump Balancer and Oil Pan

    Runs on Premium 91-93 Octane
  • Application List



    • 117-422
    • 117-422
    • Mast Motorsports
    • Special Order Item
    • New

    Shipping Information

    • Item Requires Shipping
    • 500.0 lbs.
    • FREE 48 State Shipping

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