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Ford Performance 3.73 Gears and Install Kit (86-09 V8)

Market Price $319.99 You Save 16% ($50.00)
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$269.99 (kit)

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  • Item 100576
  • MPN# 100576

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    Features & Details

    • Money Saving Combo Kit
    • Ford Racing 3.73 Gears - 8.8"
    • Motive 8.8" Rear End Installation and Bearing Kit
    • 1 Bottle of Ford Racing Friction Modifier
    • 2 Quarts of Royal Purple Max Gear 75w90 Gear Oil
    • Fits 1986-2009 V8 with 8.8" Solid Rear Axle
    Improve ET's and low end torque. Are you looking to get more low end grunt off the line and lower ET's at the same time? Then look no further than installing a set of steeper gears in your Pony. This Ford Racing Ring and Pinion Gears are perfect for street, road, or race use.

    Complete Kit. This Ford Racing Gear and Installation Kit comes complete with all the components needed to swap out your ring and pinion gear. It includes Ring gear, Pinion gear, 1 bottle of Friction Modifier, 2 bottles of 75w90 Gear Oil, gaskets, seals, shims, bearings and all the required hardware.

    Legendary Ford Racing Quality. When you're adding performance parts to your Pony, you can't go wrong by installing parts from the folks that know it best. Ford Racing's legendary quality ensures years of hassle-free use.

    Recommended Upgrade. Changing the rear axle gear ratio will throw off the calibration of your Mustangs speedometer, but a Speedometer Gear, a Ford Racing Speedometer Recalibration Tool or a Bama SF4/X4 Power Flash Tuner is a quick and easy way to fix this issue.

    Application. This Ford Racing 3.73 Rear Gear and Installation Kit is designed for use with 8.8in solid rear axle equipped Mustangs, including the 1986-2009 GT, Bullitt, Mach 1, Shelby GT500 and 1994-1998 SVT Cobra. It will not fit the 1999-2004 IRS equipped Cobra Mustangs.

    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 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 Details

    What's in the Box
    • (1) Ring gear
    • (1) Pinion gear
    • (1) 3.8 fluid oz bottle of Friction Modifier
    • (2) one quart bottle of Royal Purple Max Gear 75w90 Gear Oil
    • Front & Rear Pinion Bearing
    • Pinion Seal
    • Carrier Bearings
    • Carrier Shims
    • Differential Bearings
    • Crush Sleeve
    • Pinion Nut
    • Cover Gasket
    • Ring Gear Bolts
    • Brush
    • Gear Marking Compound
    • Loctite
    Installation Info
    Will it fit my Mustang?
    • Bullitt - 01, 08, 09
    • Cobra - 93, 94, 95, 96, 97, 98
    • Cobra R - 93, 95
    • GT - 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 00, 01, 02, 03, 04, 05, 06, 07, 08, 09
    • GT500 - 07, 08, 09
    • LX - 87, 88, 89, 90, 91, 92, 93
    • Mach 1 - 03, 04
    • Other - 86

    People Who Bought This Item Also Bought

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    23 Questions / 6 Answers

    Ask a Question

    What gears come stock on 2008 GT?

    Anonymous

    • For 2008 GT's with manual transmissions will have a 3.55 whereas the stock GT's with an automatic in a 2008 Mustang will be 3.31.

      KevinD92

    Helpful (2)

    If i get this kit for my 97 gt automatic what Speedo gear do i need to fix my speedometer?

    Anonymous

    • The Ford Performance 3.73 Gears and Install Kit will require a new speedometer gear, however, depending on the tooth count on the drive gear, the appropriate gear may vary. If your Mustang has a 6 tooth drive gear, you will need item #383922. If your Mustang has a 7 tooth drive gear, you will need item #53685. If you Mustang has a transmission with an 8 tooth drive gear, you would technically need a 25 tooth gear, however, that was not an available option, and would would need to be made for your application.

      AMJEFF

    Helpful (2)

    I've seen others ask about the rear wheel/axle bearings do they need to be changed out when buying this kit or does it not matter

    MikeR

    • The rear axle bearings would not need to be changed out when doing this kit however it would not be a bad thing to change them out so everything is new!

      Ricky36

    Helpful (1)

    Do you have a similar product for 3.9l v6?

    Texvape44

    • We do not have a gear and install kit for the 3.9L V6 motor.

      KevinD92

    Helpful (1)

    Will these help my 03 gt convertible. Looking for speed but wanting to keep the car stock ish if you know what I mean.

    Anonymous

    • Larger gears will definitely aid the car in taking off faster. Though, to gain performance you can also add a cold air intake and a better flowing exhaust.

      AshleyK

    Helpful (1)

    What's the difference between this kit and the one for the 10-14 mustangs? Aren't all GT differentials the same from 05-14?

    JeremyJAK

    • There are two differences between the Ford Performance 3.73 Gears and Install Kit (86-09 V8) and the Ford Performance 3.73 Gears and Install Kit (10-14 V8; 11-14 V6) (Item #100573) 86-09 has 75w90 gear oil where 10-14 has 75w140. 10-14 also has Ford Rear Gear Pinion Bearing - 8.8in (10-14 V8; 11-14 V6) (Item #52994) where the 86-09 kit does not.

      JeffAM

    Helpful (1)

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    Customer Reviews (100+) Write a Review

    Overall Rating 4.7

    out of 5 stars

    Installation Time:Weekend

    Installation Cost:$250-$500

    • Performance Gain 4.650486 4.7
    • Fit 4.757282 4.8



    • 5/5

      Installation Time: Afternoon

      February 01, 2018

      Gears for everyone

      Good gear ratio for a daily driver. Also didn’t affect the gas mileage much. I should of done this a long time ago. Would recommend this for everyone

      KevinA

      Year: 1996 Submodel: GT

      Helpful (1)

    • 5/5

      Installation Time: Afternoon

      January 20, 2018

      3:73 gears

      should of went with lower gears maybe 4:11 but they worked fine

      Bob

      Year: 2006 Submodel: GT

      Helpful (0)

    • 4/5

      Installation Time: Afternoon

      January 06, 2018

      Gears

      Great product great price easy install. Recommend everyone to use American Muscle.

      korys

      Year: 1990 Submodel: GT

      Helpful (0)

    • 5/5

      Installation Time: Afternoon

      November 27, 2017

      373 gear

      Excellent product, fast shipping, awesome customer service...

      Allen

      Year: 2003 Submodel: GT

      Helpful (0)

    • 1/5

      Installation Time: Shop Install

      Installation Cost: $1000+

      November 20, 2017

      No stars!!!!

      Tried to get one over on me! Send me used gears!!!! Car still apart waiting for A.M. to make it right! Very unsatisfied!! Go figure they wont let me give no star!!

      GregL

      Year: 1992 Submodel: LX

      Helpful (2)

    • 3/5

      Installation Time: Full Day

      November 05, 2017

      Gears great/ Kit not

      I love the gears, and the added umph coming off the line. However, the gear marking compound was dried out, so my mechanic set everything as best he could. Also, the gasket for the diff cover has developed a leak, and he regrets not using RVT.

      ChrisY

      Year: 2005 Submodel: GT

      Helpful (1)

    • 5/5

      Installation Time: Afternoon

      October 17, 2017

      great upgrade

      very good up grade to your mustang wakes it up nice with the other mods have done

      Ericc

      Year: 2006 Submodel: GT

      Helpful (0)

    • 4/5

      Installation Time: Shop Install

      Installation Cost: $250-$500

      September 01, 2017

      Up the gears

      I trust American muscle so I purchased my new 373 gear kit from them. I took my cobra to Lamatta performance in Cassleberry fl. to have the gears installed and he knew exactly what they were sending. He used most of the parts sent, but he prefers using a different and he says better quality of rings. He says he uses his rings on all his gear upgrades. Lamatta's has ALWAYS done quality work on my cobra, and his reputation is undisputed.

      DavidF

      Year: 1997 Submodel: Cobra

      Helpful (0)

    • 5/5

      Installation Time: Afternoon

      August 20, 2017

      Good priduct

      Definetly worth the money feel the difference all around I also bought the carbon track lock kit as well .. I recommend a lift because you have so l8ttle room on jacks ..

      Dubs

      Year: 2006 Submodel: GT

      Helpful (0)

    • 5/5

      Installation Time: Shop Install

      Installation Cost: $500-$1000

      August 01, 2017

      I wish i would have done it sooner

      These are pretty swèet and definitely and good upgrade but good luck trying to fix the speedometer.

      Shorty17

      Year: 1997 Submodel: GT

      Helpful (0)

    • 5/5

      Installation Time: Full Day

      July 30, 2017

      Woke up

      Totally woke up the responsiveness of the throttle makes the car totally come alive. Try to plan a whole day for install, doesn't take the full day just make sure you do it right

      Louie

      Year: 2003 Submodel: GT

      Helpful (0)

    • 5/5

      Installation Time: Full Day

      July 28, 2017

      Good grunt off the line

      Nice takeoff...wayyyy better than those factory gears....really feel it digging off the line nd getting out of there....money well spent

      Dee

      Year: 2003 Submodel: GT

      Helpful (0)

    • 5/5

      Installation Time: Shop Install

      Installation Cost: $250-$500

      July 15, 2017

      Great salection

      The best gears on the market i belive they never made a noise and perform really well. Is a day and night difference from 3.31

      MartinH

      Year: 2008 Submodel: GT

      Helpful (0)

    • 4/5

      July 03, 2017

      Good Kit

      Payed a shop to install this kit in my manual 2000 GT. Worked as described. I will say the performance wasn't as great as some people make it out to be. (My car is now full bolt-on for reference.) While I did notice a difference, I think some people exaggerate the gains from gears in these cars.

      cl0udedth0ught

      Year: 2000 Submodel: GT

      Helpful (0)

    • 5/5

      Installation Time: Shop Install

      Installation Cost: $100-$250

      June 26, 2017

      Great Bang For the Buck

      This is one of the best bang for the buck deals out there. I bought it along with a trac lok rebuild kit and saved money on the shop labor. A hug difference in "seat of the pants" feel. A little bit of whining during break in but not loud enough to be annoying.

      Jonesy

      Year: 1988 Submodel: GT

      Helpful (1)

    • 2/5

      Installation Time: Full Day

      June 22, 2017

      Not so good

      Some of the seal didn't fit. My mechanic said lubrication oil was wrong. The bearings were wrong as well. So I pretty much had to buy more stuff to get what is needed

      porhewitt

      Year: 2008 Submodel: GT

      Helpful (1)

    • 5/5

      Installation Time: Afternoon

      June 22, 2017

      Ford performance 3.73 gears

      I installed these 373 gears on my 2002 Mustang GT and it made a huge difference on the low end. Car feels so much stronger and every gear at Pulls very hard. Definitely worth the money.

      MyrtF

      Year: 2002 Submodel: GT

      Helpful (0)

    • 4/5

      Installation Time: Shop Install

      June 21, 2017

      Not bad

      The kit comes with everything you need which is great. Reason why I gave it a 4 is because it wasn't as much of a difference, I just went for it since everyone was saying 4.10 was too much.

      DanielH

      Year: 2009 Submodel: GT

      Helpful (0)

    • 2/5

      Installation Time: Afternoon

      June 11, 2017

      Ford Performance 3.73 Gears and Install Kit

      Fast shipping.I will review this in 3 parts so you can understand the 2 star rating iI gave Part 1 the ring and pinion is excellent top notch no complaints hard to beat Ford OEM quality 2 thumbs up. Part 2 install kit this is where I give it a thumbs down.The bearings in the install kit are not of the best quality 2 of the bearings had faulty bearing cages so I had to purchase 2 extra bearings. so $60 later I was back in business.Part 3 supplied oil.Great quality oil but not enough to properly fill the diff.The diff takes 2 1/2 quarts and only 2 are included.Off to the store again to buy more oil.This is for the crew at American muscle. provide a better quality install kit and 3 quarts of oil instead of 2 for this package.

      Dannyboy

      Year: 1992 Submodel: LX

      Helpful (1)

    • 5/5

      Installation Time: Afternoon

      June 09, 2017

      Great choice here

      I am very happy with the gear choice. My s197 is not a daily driver so I wanted a little more acceleration. Cruising on the highway at 80 with off-road exhaust I was worried about noise and Rpm's. Glad I made the choice.

      JamesW

      Year: 2007 Submodel: GT

      Helpful (1)

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