THE STRONGBOX UNDERDRIVE SERIES

Powerful Underdrives for Dana 300s, NP205s, Rangers and more.

To find the right model for your build, please enter the your transmission output, and transfer case input below to see the Strongbox models that fit your vehicle:

Drivetrain Length Specs by Model

Standard NP241 32 Spline Strongbox - Adds 8 Inches to Drivetrain Length

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Standard NP241 31 Spline Strongbox - Adds 8 Inches to Drivetrain Length

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Standard NP241 23 Spline Strongbox (S) - Adds 8 Inches to Drivetrain Length

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Standard NP241 23 Spline Strongbox (L) - Adds 8 Inches to Drivetrain Length

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NP241 Dana 300 SHORTY Strongbox - Adds 5.5 Inches to Drivetrain Length

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NV241 Strongbox for NP205 90mm Spline - Adds 5.5 Inches to Drivetrain Length

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NV241 Strongbox for NP205 80mm Spline - Adds 5.5 Inches to Drivetrain Length

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Ranger Standard Strongbox - Adds 7 Inches to Drivetrain Length

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Ranger SHORTY Strongbox - Adds 4.4 Inches to Drivetrain Length

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Standard NV271 32 Spline Strongbox - Adds 8 Inches to Drivetrain Length

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Standard NV271 31 Spline Strongbox - Adds 8 Inches to Drivetrain Length

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Standard NV271 23 Spline Strongbox (S) - Adds 8 Inches to Drivetrain Length

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Standard NV271 23 Spline Strongbox (L) - Adds 8 Inches to Drivetrain Length

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NV271 Dana 300 SHORTY Strongbox - Adds 5.5 Inches to Drivetrain Length

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NP271 Strongbox for NP205 90mm Spline - Adds 5.5 Inches to Drivetrain Length

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NP271 Strongbox for NP205 80mm Spline - Adds 5.5 Inches to Drivetrain Length

Have Technical or Compatibility Questions?

Have questions about compatibility or specific technical questions for your build?

Give our team a call at (855) 928-1984 and one of our staff engineers will gladly help step you through aspect of compatibility, and the build process you need.