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Nitro Gear & Axle Ring and Pinion Gear Kit; 3.90 Gear Ratio (99-04 GT)

Item 404774
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Market Price $264.50 You Save 9% ($23.00)
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$241.50 (kit)

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      Product Information

      Features, Description, Reviews, Q&A, Specs & Installation


      • Performance Ring and Pinion Kit
      • Upgrade Your Mustang’s Gears
      • 3.90 Gear Ratio
      • 8.80-Inch Ring Gear Diameter
      • Heavy-Duty 8620 Steel Construction
      • Professional Installation Recommended
      • 2-Year Warranty
      • Fits 1999-2004 Ford Mustang GT Models


      Ready to Go. When you’re looking for an upgrade for your 1999-2004 Ford Mustang GT, one of the ways to optimize your vehicle is with the Nitro Gear & Axle Ring Gear and Pinion Kit – 3.90 Gears. Their heavy-duty 8.80-inch construction and high-quality material will provide you with optimal power transference and torque for years to come.

      3.90 Gears. This kit’s ring gear has a 3.90 ratio, which can improve your Mustang’s fuel efficiency without compromising performance. It’s a great way to ensure that all the torque and horsepower your engine has is being utilized to its full potential.

      Durable Construction. This ring and pinion are both forged from 8620 grade steel, which protects against heat and wear and tear better than any other metal on the market. They will last for years to come.

      Recommended Upgrade. This ring and pinion will require a re-tuning of your Mustang’s computer if you’re changing the gear ratio. This can be done with a simple car tuner if you have one available.

      Installation. This ring and pinion kit is a very advanced kit to install. Advanced mechanical expertise is required to install with advanced tools. Please allow about 4 hours, minimum, for manual installation, but professional installation is highly recommended due to the intricacy of the task.

      2-Year Warranty. This ring and pinion kit has been protected by Nitro’s 2-year warranty, defending against manufacturer defects from the date of purchase. See Nitro Gear’s full warranty for complete details.

      Application. This Nitro Gear & Axle Ring Gear and Pinon Kit – 3.90 Gears is designed to fit 1999-2004 Ford Mustang GT models. Please ensure correct model and trim before purchase.

      Fitment: 1999 2000 2001 2002 2003 2004 Details

      Nitro Gear & Axle F8.8-390-NG

      CA Residents: WARNING: Cancer and Reproductive Harm -

      Installation & What's in the Box

      Installation Info

      What's in the Box

      • (1) Ring Gear
      • (1) Pinion

      Customer Reviews (3)

        Reviews of Nitro Gear & Axle Drivetrain products have an average rating of 4.5 out of 5

          Questions & Answers

          10 More Questions

          Will It Fit My Mustang

          • Bullitt - 01
          • GT - 99, 00, 01, 02, 03, 04

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