Driving Innovation In Diesel Performance

Machined Blocks. Built for Cummins.

Finish-machined Cummins blocks for DIY engine builds. CNC bored/honed with a torque plate, deck resurfaced, and cleaned.

Tap Compare on up to 3 products. When you’ve selected 2+, use Compare products at the bottom.

Price $963.99
2003-2007 5.9 COMMON RAIL D&J HP REMAN BLOCK

2003-2007 5.9 COMMON RAIL D&J HP REMAN BLOCK

  • Rigorously inspected, heat-cleaned, and shot blasted
  • CNC bored and deck resurfaced (typically +.020 over)
  • Torque-plate CNC honed to Cummins spec
  • Main clearance verified; new cam bushing installed
Shop Now
Price $963.99
2007.5 - 2018 6.7 CUMMINS D&J HP REMAN BLOCK

2007.5 - 2018 6.7 CUMMINS D&J HP REMAN BLOCK

  • Rigorously inspected, heat-cleaned, and shot blasted
  • CNC bored and deck resurfaced (typically +.020 over)
  • Torque-plate CNC honed to Cummins spec
  • Main clearance verified; new cam bushing installed
Shop Now
Price $4,069.99
2007.5 - 2018 6.7 CUMMINS D&J PERFORMANCE SERIES BLOCK

2007.5 - 2018 6.7 CUMMINS D&J PERFORMANCE SERIES BLOCK

  • CNC bored and deck resurfaced (typically +.020 over)
  • Torque-plate CNC honed to Cummins spec
  • Billet girdle + 9/16 main studs; line bore/hone
  • Cam tunnel line honed with bushings installed
Shop Now
Price $4,069.99
2003-2007 5.9 CUMMINS D&J PERFORMANCE SERIES BLOCK

2003-2007 5.9 CUMMINS D&J PERFORMANCE SERIES BLOCK

  • CNC bored and deck resurfaced (typically +.020 over)
  • Torque-plate CNC honed to Cummins spec
  • Billet girdle + 9/16 main studs; line bore/hone
  • Cam tunnel line honed with bushings installed
Shop Now
KNOWLEDGE HUB

Everything you need to know about D&J Cummins machined engine blocks.

Choose HP Reman Blocks for a budget-friendly, finish-machined foundation (inspection, cleaning, CNC bore/deck, torque-plate hone). Step up to Performance Series Blocks when you want high-horsepower bottom-end support with a billet girdle, 9/16 main studs, and cam tunnel work, built for more load and more boost.

  • Finish-machined for DIY builds Ready-to-assemble block options for Cummins builders who want D&J machining without a full engine build.
  • CNC bore + deck surfacing Blocks are typically bored and the deck resurfaced, then finished to spec for clean sealing.
  • Torque-plate CNC honing CNC honed to Cummins spec using a torque plate for better ring seal and cylinder consistency.
  • Main bore measured and corrected Main bearing clearance is checked and line honed as needed to keep the bottom end true.
  • Performance Series bottom-end support Performance Series blocks add billet girdle + 9/16 main studs with line bore/hone and full cam tunnel/bushing work.

FAQs

Are these complete engines?
No, these are finish-machined blocks sold as ready-to-assemble foundations for DIY engine builds.
What’s the difference between HP Reman and Performance Series blocks?
HP Reman focuses on finish machining and cleanliness; Performance Series adds billet girdle/9⁄16 main studs plus cam tunnel work for higher-load builds.
Are the cylinders bored and honed?
Yes, blocks are bored and deck resurfaced (often +.020 over) and CNC honed to spec with a torque plate.
Are main bores line honed?
Main clearance is measured and line honed as needed; Performance Series blocks are line bored/line honed with the girdle and main studs.
Do the blocks include cam bushings?
Yes, HP Reman blocks list a new cam bushing installed after machining; Performance Series blocks list cam tunnel line hone and bushings throughout.
Do you ship standard-bore blocks?
Most blocks are not standard bore many are machined to +.020 over based on core condition and inspection.
What should I do before final assembly?
Clean everything again, chase threads, and verify all clearances with your fasteners before assembling the short block.
Are blocks inspected for cracks before machining?
Yes, blocks are inspected and graded in the core department and only shipped if they meet strict standards.