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MTM111-422 -Mast Motorsports Turnkey LSX 440 SS (660hp), Includes M-90 DBW ECM and Harness

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

Availability: Item has been discontinued and is no longer available
Shipping: FREE 48 State Shipping


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 with a forged Callies rotating assembly with Mahle pistons that is topped off with Mast Motorsports CNC LS7 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 CNC LS7 Heads
Intake: GMPP LS7 Intake
Valve Springs: Mast Double Nitrided .700 Lift

Part Number: 111-422

Application List



  • 111-422
  • 111-422
  • Mast Motorsports
  • Item has been discontinued and is no longer available
  • New


Shipping Information

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

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