Big Power 427 Aluminum Assembled LSR Short Block

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  • Regular price $ 14,500.00
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1,500 HP Capable

Choose a premium LSR short block assembled and proven by Mast Motorsports.  Assembled with MADE in the USA parts
Choose Either:

427 Cubic Inch

  • LSR Standard Deck Block
  • ARP Hardware
  • Callies Magnum Crank
  • Callies Ultra Rods
  • 4.125 Bore
  • 4.000 Stroke
  • 6.125 Rod Length
  • Compression Height 1.105
  • Wiseco Premium Coated Piston

LSR Block Features

  • 100% Made in USA
  • 356 T6 Premium Aluminum
  • Spun Ductile Iron Sleeves
  • Cross Braced Lifter Valley with Individual Drain Backs
  • 40% larger Main Cap Surface with a Double Crossbolt Option
  • Short or Tall deck blocks feature a Heavy Duty 0.750" deck thickness
  • Added Stock to the Front and Rear Valley Walls
  • Added 7th Transmission Bolt Hole to Accept Early Style GM Transmission
  • Maximized Cranksaddle Radius​
  • Front Oil Feed Line Can Be Restricted for Mechanical Lifter Options
  • 6 Bolt Cylinder Head Pattern
  • All OEM LSX parts such as covers, pans and accessories work seemlessly with the LSR


LSR Block Specs

  • Standard Deck:  9.240"
  • Tall Deck: 9.720
  • Bore Range: 4.065-4.190
  • Weight: 113lbs w/main caps


 LSR Block Options

  • ARP Main Stud Options
  • Cam Bore Can Be Machined to Accept 60mm Roller Bearings
  • Lifter Bore can accept larger bore or key way style lifter
  • Double Cross Bolt Option- Increases to 8 Bolt Main


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