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Richmond Ring Gear and Pinion Kit - 3.55 Gears (99-04 GT)

Market Price $258.51 You Save 9% ($23.50)
Our Price

$235.01

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  • Item 66502G99
  • MPN# 66502G99

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Features & Details

  • Exceptional Quality
  • Handle Extreme Torque Applications
  • First-Run, Never Recycled Materials
  • 3.55 Gear Ratio
  • 8.8" Ring Gear Diameter
  • 2-Year / 100,000 Mile Warranty
  • Fits 1999-2004 GT Mustangs
Better Acceleration. If you're looking to improve your rear gear ratio, but don't want to go too steep or lose much gas mileage, then these 3.55 Richmond Gears are perfect for your application. Designed for 8.8" rears found in 1999-2004 GT Mustangs, this ratio will get your Pony into the power band faster and deliver better acceleration.

Superior Quality. Manufactured right in the United States, Richmond Gear uses only the highest standards to produce the highest quality gears in the industry. Inspected and scrutinized to deliver gears with acceptable tolerances, durability and fit, Richmond ensures only the best in machining, finishing and heat treating of their drivetrain components.

Recommended Upgrade. When changing the gear ratio of your Mustang's rear differential, the calibration of your speedometer will no longer be accurate and will display the wrong speed. However, you can easily fix this annoying issue with a Tuner or Recalibration Tool (sold separately).

Installation Notes. An Installation and Bearing Kit is highly recommended by most installers, especially on high mileage Mustangs. Please see ordering options above.

Warranty. Richmond Gears is so confident in the high quality of their ring and pinions that they are backed by a 2-Year / 100,000 Mile No-Nonsense Warranty.

Application. These Richmond 3.55 Ring and Pinion Gears will fit all 1999 to 2004 GT Mustangs equipped with an 8.8" rear end.

Technical Note. Installation costs will vary, but a good rule of thumb is between $250 and $300. Be sure to work with a reliable shop that you trust for installations. You can also save money on your installation labor by having your Trac-Lok rebuilt at the same time your gears are installed. See ordering options above. Note, a 28-spline S-Spring will be required for 28-spline Mustangs (sold separately) if you opt for the Trac-Lok rebuild.

Fitment: 1999 2000 2001 2002 2003 2004 Details

What's in the Box
  • (1) Ring Gear
  • (1) Pinion Gear
Installation Info
Tech Specs

Approximate RPM for 1999-2004 GT


Manual
Gear @25 MPH @35 MPH @45 MPH @55 MPH @65 MPH @75 MPH
1 3700 5180 6660      
2 2190 3065 3941 4817 5693 6569
3 1445 2023 2601 3179 3757 4335
4 1095 1533 1971 2408 2846 3284
5 744 1042 1340 1638 1936 2233


Automatic
Gear @25 MPH @35 MPH @45 MPH @55 MPH @65 MPH @75 MPH
1 3109 4353 5596 6840    
2 1697 2376 3054 3733 4412 5091
3 1095 1533 1971 2408 2846 3284
4 766 1073 1379 1686 1992 2299
Will it fit my Mustang?
  • GT - 99, 00, 01, 02, 03, 04
  • Bullitt - 01

Most Helpful Reviews

5/5
Perfect InBetween

Looking for a In Between gear setting? Best choice by far. Won't impact daily driving but when you want, you have more pick up and go!

Helpful (1)

4/5
Costly but Good Quality

These gears will definitely improve you 4.7 in the best of ways. The car sounds a lot more aggressive and you are able to get the full potential in power out of the motor. Would definitely recomend to ...

Read More
Helpful (1)

Overall Rating 4.5 out of 5 stars
Read All 2 Reviews

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Customer Reviews (2) Write a Review

Overall Rating 4.5

out of 5 stars

Installation Time:Afternoon

  • Performance Gain 4.5 4.5
  • Fit 5 5



  • 5/5

    Installation Time: Afternoon

    January 11, 2017

    Perfect InBetween

    Looking for a In Between gear setting? Best choice by far. Won't impact daily driving but when you want, you have more pick up and go!

    Ruck

    Year: 2001 Submodel: GT

    Helpful (1)

  • 4/5

    Installation Time: Afternoon

    January 10, 2017

    Costly but Good Quality

    These gears will definitely improve you 4.7 in the best of ways. The car sounds a lot more aggressive and you are able to get the full potential in power out of the motor. Would definitely recomend to anyone looking to purchase them.

    Tony

    Year: 2004 Submodel: GT

    Helpful (1)

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