HEMI® GEN III Aluminum Blocks

HEMI® GEN III Aluminum Blocks

Hemi Gen III Aluminum Blocks are 100 pounds lighter than 6.1L production cast iron blocks! They are designed to accommodate all parts from a 6.1L Hemi Gen III engine.


  • Lightweight aluminum gives added performance in more ways than one - better acceleration, braking, vehicle dynamics, weight distribution, you name it. Lighter is better.
  • Water jackets have been completely re-designed to accommodate a Siamese bore. Extensive Computational Fluid Dynamics (CFD) studies have been performed to balance thermal conditions for consistent and reliable performance.
  • Crankcase clearance designed for a 4.125" stroke crankshaft. A 4.250" stroke will fit with machining around the oil drain backs.
  • The main bearing supports and the bottom end of the block have been completely redesigned for the additional strength required for a forced induction 440+ cubic inch motor.
  • 8620 HR billet steel main caps with four-bolt center caps beef-up the bottom end for severe performance applications.
  • Capable of supporting a dry sump package for reduced windage and to allow more engine installation options, including lower vehicle center of gravity.
  • Camshaft bearing support area increased to permit the use of a 60 mm roller bearing, if desired.
  • Lifter bores can be opened to 1.060" for a bushed-style lifter.
  • Additional boss in the front timing chain area for an idler (double roller chain). Additional boss for a front gear drive, plus attachments for a front motor plate.
  • All HEMI Gen III dress items fit Gen III Aluminum Blocks (front cover, oil pan, oil filter mounting. Front End Accessory Drive (FEAD), etc.)


  • P5155507 Block, Aluminum, 426 Hemi, Gen III, Bored at 4.125", Can Be Bored Up to 4.155"
  • P5153897 Block, Aluminum, 6.1L Hemi, Finished Bored at 4.055"
  • P5153898 Block, Aluminum, 6.1L Hemi, Semi-Finished Bored at 4.114". Can be Bored Up to 4.185"
  • P5155630 Block, Aluminum, Hemi Gen III, Semi Finished Builder's Special
List Price: $4,485.00
Price: $4,099.95
SKU: P5155507 / P5153897 / P5153898 / P5155630