1,500 HP Capable
Choose a premium LSR short block assembled and proven by Mast Motorsports. Assembled with MADE in the USA parts
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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