SMALL-BLOCK
BLOCKS AND
COMPONENTS

SMALL-BLOCK
BLOCKS AND
COMPONENTS

Where winning begins

Build for the street, the strip, or both with power factory-engineered to compete.

PRODUCTION-BASED BLOCKS

When building a performance engine or replacing a stock engine, our production-based blocks offer the strength, accuracy, and peace of mind you’d expect from Chevrolet Performance.

Production-Based Blocks Technical Notes

  • Standard 350 main journal sizes
  • Non-Siamese bores
  • Production-spec cylinder wall thickness
  • Lifter valleys machined for hydraulic-roller and flat-tappet valvetrains  

BOWTIE SPORTSMAN BLOCKS

These highly versatile blocks are available in a variety of finish options for maximum flexibility, providing a rock-solid foundation for any drag strip, circle track, or high-performance application in the 300-500-horsepower range.  

Bowtie Sportsman Technical Notes

  • Standard 9.025-inch deck height
  • Nominal cylinder wall thickness is 0.340-inch
  • Minimum cylinder wall bore thickness on 4.155-inch bore is 0.225-inches (excluding P/N 10051181, 10051183, and 10185047)
  • Extra-thick deck surfaces have blind-tapped bolt holes for improved head gasket sealing
  • Priority main oiling system
  • Main bearing bulkheads are 0.900-inch thick and use Grade-8 bolts
  • All five cam bearing locations require 2.000-inch O.D. (1.867-inch I.D.) bearings P/N 12370843 (except block P/N 10051183)
  • Tall lifter bore blocks may require clearancing the top of the lifter bores for some roller lifters
  • Lifter valley oil scavenging boss below bell housing flange is present, but not drilled and tapped
  • Oil dipstick holes are not drilled
  • Timing system clearance must be checked

RACE BLOCKS

From start to finish line, precision is the operative word with high-grade materials and machining techniques, and proven stock Car and drag racing performance heritage.   

Race Block Technical Notes

  • Precision CNC-machining means +/- 0.001-inch tolerances.
  • Cylinder bore wall thickness is 0.225" minimum at 4.155" bore. A sonic bore check data sheet is provided with block
  • Nominal wall thickness of cylinder bores is 0.340"
  • Cylinder decks, front and rear of case, oil pan rail surfaces and head dowel pins are blueprinted
  • Extra-thick deck surfaces have blind-tapped head bolt holes for superior head gasket sealing
  • Enlarged cam bosses allow custom machining for larger bearings
  • Non-standard cam bearings are required (see each block for details)
  • Extra-thick main bearing bulkhead is machined at 5°
  • Bearing cap inner bolts are spread 0.210" to allow machining for 400 journal crankshafts
  • Premium quality main studs and SAE 8620 steel main bearing caps
  • Priority main oiling system
  • Billet wet sump rear main cap can be adapted to dry sump with plugs
  • 2-piece rear main crankshafts and pre-1986 oil pans are required
  • Use of some aftermarket mechanical roller lifters may require clearancing top of lifter bores
  • Timing system clearance should be checked before engine assembly
  • Lifter valley oil scavenging boss below bell housing flange is not drilled or tapped
  • Oil dipstick holes are not drilled

ALUMINUM RACE BLOCKS

Aluminum race blocks provide competition-level strength and reliability for road racing or high horsepower turbocharged applications.

Aluminum Race Blocks Technical Notes

  • Extra-thick deck surfaces with blind-tapped head bolt holes for improved head gasket sealing
  • Centrifugally spun cast-iron cylinder sleeves
  • 2-piece rear-main crankshafts and pre-1986 oil pans required
  • Enlarged cam bosses allow machining for larger cam bearings
  • 2.000" O.D. (1.867" I.D.) cam bearings P/N 12370843 required
  • Blocks may require clearancing at top of lifter bores (0.842") for some roller lifters
  • Timing system clearance should be checked before engine assembly
  • Extra-thick main bearing bulkhead machined at 5°
  • Premium main studs and steel main bearing caps
  • Priority main oiling system Billet wet sump rear main cap can be converted to dry sump with plugs
  • Oil dipstick holes not drilled

CYLINDER BLOCK COMPONENTS

Learn More

FRONT COVERS, TIMING POINTERS,
FUEL PUMP BLOCK OFF-PLATE

Learn More

CYLINDER BLOCK COMPONENTS

FRONT COVERS, TIMING POINTERS,
FUEL PUMP BLOCK OFF-PLATE

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Unless specifically noted to the contrary herein, vehicles equipped with Chevrolet Performance parts that are emissions-related may not meet U.S., Canadian, and state and provincial laws and regulations relating to motor-vehicle emissions. These parts are designed and intended for use in vehicles operated exclusively for competition: in racing or organized competition on courses separate from public streets or highways. Visit www.chevroletperformance.com/emissions for more details.