Driving Innovation In Diesel Performance

Stage 3 Heads. Built for Cummins.

Stage 3 Cummins heads are designed for extreme high-performance 6.7L builds (4.212” bore or larger)

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From $7,678.99
6.7L Stage 3 24v Cummins Performance Head

6.7L Stage 3 24v Cummins Performance Head

  • For 6.7L (4.212” bore+) extreme performance applications only
  • D&J Stage 3 billet intake manifold designed to keep key factory components
  • 5-axis CNC porting + increased intake flow to 300 CFM (vs 165 stock)
  • Heavy-duty seats + thread-in soft plugs to prevent common high-HP failures
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Price $9,502.50
6.7L Stage 4 24v Cummins Performance Head

6.7L Stage 4 24v Cummins Performance Head

  • For 6.7L (4.212” bore+) extreme performance applications only
  • D&J Stage 4 billet runner intake with reusable O-ring seals for equal cylinder airflow
  • 5-axis CNC porting + increased intake flow to 320 CFM (vs 165 stock)
  • Heavy-duty seats + thread-in soft plugs for high-demand durability
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How the Stage 3 Cummins Head Is Built

Take a look at the step by step process to build the best Cummins head on the market.

KNOWLEDGE HUB

Everything you need to know about D&J Cummins stage 3 cylinder heads.

Stage 3 builds on the Stage 2 foundation with a D&J Stage 3 billet intake manifold plus oversize super alloy valves and reliability upgrades, with stated intake flow increased to 300 CFM (vs 165 stock). Stage 4 adds a billet runner-style intake built for equal airflow to all cylinders (reusable O-ring seals) and stated intake flow increased to 320 CFM (vs 165 stock)—targeting more consistent EGTs across cylinders.

  • High Airflow Gains Stated intake flow increases to 300 CFM (Stage 3) or 320 CFM (Stage 4) compared to 165 CFM stock.
  • Heavy-Duty Intake Seats Extra-large intake seats address stock seat failure concerns in high-horsepower applications.
  • Thread-In Soft Plugs Thread-in soft plugs help prevent under-cover soft plug failures that can dump coolant into the crankcase.
  • Oversize Super Alloy Valves Oversize super alloy valves are included for durability and performance under extreme heat/load.
  • Precision CNC Porting 5-axis CNC porting is part of the build process to support airflow and efficiency.

FAQs

What is a Stage 3 6.7 Cummins performance head?
Stage 3 adds a D&J Stage 3 billet intake manifold plus oversize valves and reliability upgrades, for 6.7L 4.212” bore+ builds.
What is a Stage 4 6.7 Cummins performance head?
Stage 4 includes everything in Stage 3 plus a D&J billet runner-style intake designed for equal cylinder airflow on 6.7L 4.212” bore+ builds.
What’s the difference between Stage 3 and Stage 4?
Stage 4 upgrades to a runner-style intake for equal airflow and adds stated flow increase to 320 CFM vs Stage 3’s 300 CFM (both vs 165 stock).
Will these fit a 5.9 Cummins?
These Stage 3/4 heads are listed for 6.7L applications and are specified for 4.212” bore or larger.
Why do you use heavy-duty extra-large intake seats?
They’re intended to address stock intake seat failure issues seen in extreme horsepower applications.
Why are thread-in soft plugs important?
They help prevent under-cover soft plugs from dislodging and filling the crankcase with coolant.
How much airflow do Stage 3/4 heads add?
The pages state intake flow increases to 300 CFM (Stage 3) or 320 CFM (Stage 4) compared to 165 CFM stock.
Do these come with an intake manifold?
Yes, Stage 3 includes a billet intake manifold, and Stage 4 includes a billet runner-style intake manifold.