Drivetrain› Differentials and Rear-End Components

Richmond

3.73 Ring and Pinion Gear Kit

$443.98

SKU: 66501G99

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In Stock
Ships by Aug 5
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30 Days Return
INSTALL DIFFICULTY
DIY PRO SHOP

Moderate — 2–4 hours

Description

The Richmond 3.73 Ring and Pinion Gear Kit offers enhanced acceleration for your 1999-2004 Ford Mustang GT, allowing you to leave the line faster and reach your power band more quickly. Manufactured in the United States, Richmond Gear ensures high standards in machining, finishing, and heat treating. This ensures gears with acceptable tolerances, durability, and fit. The kit includes a 3.73 gear ratio and an 8.8" ring gear diameter. It is backed by a 2-year or 100,000-mile warranty. When changing your differential's gear ratio, your speedometer calibration will become inaccurate. A Tuner or Recalibration Tool (sold separately) is required to correct this. An Installation and Bearing Kit is highly recommended, especially for high-mileage Mustangs. Additionally, a 28-spline S-Spring (sold separately) is necessary for 28-spline Mustangs if you opt for a Trac-Lok rebuild during installation.

MIA's Description

The Richmond 3.73 Ring and Pinion Gear Kit is designed for 1999-2004 Ford Mustang GT models with an 8.8" rear end. It features a 3.73 gear ratio and is built with first-run, never-recycled materials to handle extreme torque applications.

This kit is manufactured in the United States and is backed by a 2-year or 100,000-mile warranty.

Fitment

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Specifications

BrandRichmond
Part Number66501G99
CategoryDrivetrain

Buy with Confidence

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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