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Motive Performance Plus Ring Gear and Pinion Kit - 3.90 Gears (86-93 GT)

Market Price $297.99 You Save 12% ($35.59)
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  • Item 21102G87
  • MPN# F888390

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Ship to: Ashburn - 20149
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    Features & Details

    • Superior Quality
    • CNC-Cut from 8620 Gear Steel
    • 3.90 Gear Ratio
    • 8.8" Ring Gear Diameter
    • For Street or Track Use
    • Fits 1986-1993 GT and 5.0 LX Mustangs
    Improve Overall Performance. A set of Motive Performance gears will wake up your Pony and get it moving faster off the line. Steeper gears are a great way to lower quarter mile times and improve responsiveness without sacrificing driveability. 3.90 gears are perfect for the Pony that needs more than 3.73s but less than 4.10s, offering a great blend of performance and efficiency.

    Superior Construction & Precision Fit. These Motive ring and pinon gears are CNC cut from high grade 8620 gear steel, and factory lapped for precision fit. Each set is hardness tested prior to leaving the factory to ensure the highest quality. Unlike other brands, Motive Gears do not have a reputation for "gear whine".

    Recommended Upgrade. Changing the rear axle gear ratio will throw off the calibration of your Mustangs speedometer, but a new Speedometer Gear is an inexpensive way to fix this issue.

    Application. This Motive Performance Plus 3.90 Ring and Pinion Gear set will fit all 1986 to 1993 V8 Mustangs including the GT, LX 5.0 and Cobra models. A master bearing kit is recommended by most installers, especially on high mileage vehicles, see drop down option above.

    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 as your gears are installed, see drop down option above.

    Fitment: 1986 1987 1988 1989 1990 1991 1992 1993 Details

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

    Approximate RPM for 1986-1993 GT


    Manual
    Gear @25 MPH @35 MPH @45 MPH @55 MPH @65 MPH @75 MPH
    1 4053 5674        
    2 2393 3351 4308 5265 6223  
    3 1600 2239 2879 3519 4159 4799
    4 1203 1684 2165 2646 3127 3608
    5 806 1128 1450 1773 2095 2417


    Automatic
    Gear @25 MPH @35 MPH @45 MPH @55 MPH @65 MPH @75 MPH
    1 2886 4041 5196 6350    
    2 1764 2470 3175 3881 4586 5292
    3 1203 1684 2165 2646 3127 3608
    4 802 1123 1443 1764 2085 2405
    Will it fit my Mustang?

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    Customer Reviews (5) Write a Review

    Overall Rating 4.2

    out of 5 stars




    • 3/5

      July 14, 2010

      390

      Had gear professionally installed, greater acceleration and higher rpms, unfortunately the gear whines, would recommend ford racing, but they dont make a 390 so i chose motive because i wanted a 390, ill live w it

      Matt

      Helpful (3)

    • 5/5

      June 02, 2010

      perfect gear

      great gear not to low like 410s but still feels better then 373s.. i had gotten a rebuild kit with the gears.. i have not had any whine unless in reverse..

      chalmers

      Helpful (2)

    • 3/5

      December 05, 2009

      whine

      good compromise from 4.10s but have a tendency to whine.

      david

      Helpful (3)

    • 5/5

      September 10, 2009

      better than 4.10s imo

      Went from stock to 4.10s. that lasted about a year. Decided to go down to 3.90s. They are definatly a much more street friendly gear, but still get up and move! 3rd redlines at about 85, and 4th is around 115, so you'll definatly still have plenty of oomph to blow past the slow traffic on the freeway-

      Brian

      Helpful (3)

    • 5/5

      October 09, 2007

      Great get up and go.

      I feel that these are the great in between gears to have. I didn\'t want 3.73\\\'s but I didn\'t want 4.10\\\'s either. You will get a great improvement when you hit the throttle.

      Travis

      Helpful (1)

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