The Ultimate Frankenstein Diesel Truck

Diesel fans love to argue over which brand builds the best truck — Cummins, Power Stroke, or Duramax. But what if you didn’t have to pick just one? Imagine taking the toughest engine block from one brand, the strongest transmission from another, and the most advanced fuel system from a third. In this guide, we build the ultimate “Frankenstein” diesel truck by cherry‑picking the best OEM parts from Dodge Ram, Ford Super Duty, and Chevy/GMC HD models to create a powerhouse that blends reliability, performance, and innovation.

Engine Block: 5.9L 12-Valve Cummins (1994 to 1998)

• Why it wins:
  • Legendary durability
  • Forged internals
  • Simple design with zero electronics
  • Proven to handle over 1,000 HP with the right build
• Runner-up: 6.7L Cummins (for torque and emissions compliance)

Fuel Injection System: CP3 Modern Common Rail Injectors (2003 to 2007 Cummins or 2004.5 to 2010 Duramax)

• Why it wins:
  • CP3 is reliable and tunable
  • Bosch common rail injectors offer precise fueling
  • Plenty of aftermarket support
  • Proven on both Cummins and Duramax platforms
• Avoid: CP4 (Duramax LML and early Power Stroke 6.7L), VP44 (unless you like headaches), or early HEUI

Turbo System: Fixed Geometry S300 with Optional Compounds

• Why it wins:
  • Simplicity and spool from an S300
  • Upgradeable to compound setup for towing and top-end
  • Easier to tune and maintain than variable-geometry turbos (VGT)
• Honorable Mention: 6.7L Power Stroke VGT — good for daily driving and emissions setups

Transmission: Allison 1000 6-Speed (2006 to 2010 LBZ/LMM Duramax)

• Why it wins:
  • Best reputation in the business
  • Handles big torque with minimal upgrades
  • Smooth shifting and reliable under pressure
  • Tons of tuning support
• Runner-up: 10R140 TorqShift (2020 Power Stroke) for modern features and 10-speed efficiency

Transfer Case: NV271 Manual Shift (from older Ram trucks)

• Why it wins:
  • Simple, strong, no electronics
  • Manual lever means no motor to fail
  • Built to take abuse
• Alternate Option: BorgWarner electronic T-cases for more modern applications, if you're OK with complexity

Axles: Ford Super Duty Dana 60 Front / Sterling 10.5 Rear

• Why it wins:
  • Easy to source
  • Tons of support
  • Built for hauling
  • 35-spline rear options with locker upgrades available
• Honorable Mention: AAM 11.5 (Duramax rear axle) for big towing setups

Frame and Chassis: Ford Super Duty (2005 to 2016)

• Why it wins:
  • Built like a tank
  • Clean engine bay with room for compounds
  • Front coil-spring suspension rides better than older leaf-spring setups
• Runner-up: GM 2500HD (great ride quality, iffy front suspension for big lifts)

Interior and Electronics: Late-model GM (2017 L5P Duramax trucks)

• Why it wins:
  • Best factory interior among the Big Three
  • Modern infotainment, good ergonomics
  • Easy to live with as a daily driver
• Alternate: 2020 Ford interiors are a close second

Tuning Platform: EFI Live or HP Tuners

• Why it wins:
  • Proven track record
  • Full custom tuning support
  • Used widely in the Duramax and Cummins world
• Power Stroke options: Limited but growing (especially with EZ Lynk and SCT)

Cooling System: 6.7L Cummins Dual Radiator Setup

• Why it wins:
  • Massive cooling capacity
  • Designed to support heavy tow loads
  • Easy to upgrade with aftermarket radiators and fans

Drivability Notes

If you want the best of all worlds:

• Use a 5.9L Cummins long block
• Pair it with a modern common rail setup using a CP3
• Back it with a 6-speed Allison
• Mount it in a Ford Super Duty chassis
• Add a compound turbo setup
• Feed it clean tuning and it’ll outpull, outlive, and outrun most factory rigs

Final Thoughts: Why Frankenstein Trucks Make Sense

Sure, it’s hypothetical. But a lot of diesel builders already build "Frankenstein" setups to some degree — swapping transmissions, retrofitting injection systems, or even putting Cummins engines into Ford chassis. If you could start from scratch with a parts bin from all three brands, this setup would give you the best mix of power, reliability, simplicity, and comfort.

By: Adam