production based blocks

BIG-BLOCK PRODUCTION BASED BLOCKS

19170538

427/454 BARE BLOCK

  • New design casting incorporating the best designs of Mark IV and Gen VI
  • Production type cast-iron 4-bolt block  
  • 4.250” finished bore  
  • 4.310” max bore (non-siamese bore)   
  • Machined fuel pump pad  
  • New water jackets for use with Mark IV or Gen VI heads 
  • Revised oiling to allow for bigger cam bearings/cam lift
  • Bolt boss (not machined) added near distributor hole like 8.1L
  • Can be drilled for use with 10-bolt front timing cover 
  • Additional clearance added for roller timing chains   
  • Auxiliary oil pressure line added to front of block  
  • Racing-style oil filter cast feature with added oil pressure port
  • Additional boss for manual-transmission clutch pivot (machined)
  • Additional material added around lifter bosses  

19170540

502 MARK-IV/GEN-VI BARE BLOCK

  • New design casting incorporating the best designs of Mark IV and Gen VI
  • Production-type cast-iron 4-bolt block  
  • Improved main bearing bulkheads-Bowtie block-style bulkhead
  • Clearanced for bigger strokes 
  • 4.470” finished bore 
  • 4.600” max bore (siamese)  
  • Fuel pump pad has been added/machined 
  • New water jackets for use with Mark IV or Gen VI heads
  • Revised oiling to allow for bigger cam bearings/cam lift  
  • Bolt boss (machined) added near distributor hole like 8.1L 
  • Can be drilled for use with 10-bolt front timing cover  
  • Additional clearance added for roller timing chains   
  • Auxiliary oil pressure line added to front of block  
  • Racing-style oil filter cast feature with added oil pressure port
  • Two bosses added for manual transmission clutch pivot (machined)
  • Additional material added around lifter bosses

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Unless specifically noted to the contrary herein, vehicles equipped with Chevrolet Performance Parts may not meet Federal Motor Vehicle Safety Standards and emissions regulations and should not be operated on public roads. Chevrolet Performance customers are responsible for ensuring their use of Chevrolet Performance complies with applicable federal, state, and local laws, regulations, and ordinances. Many parts intended for racing or other “off-highway” use are not designed or tested for crashworthiness or to meet the safety needs of the motoring public, and may adversely affect the original intended performance or handling characteristics of the vehicle. These parts are designed and intended to be used with experts supervising their installation and use, to help assure the proper and safe operation of the vehicle.

  • The Manufacturer's Suggested Retail Price excludes tax, shipping and installation. Individual retailer pricing may vary. Please see your local dealer or retailer for details.

  • The Manufacturer's Suggested Retail Price excludes destination freight charge, tax, title, license, dealer fees and optional equipment. Click here to see all Chevrolet vehicles' destination freight charges.