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BBK Underdrive Pulleys (Late 01-04 GT)

Item 56008
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Market Price $192.09 You Save 12% ($22.10)
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$169.99

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    Features & Details

    • Gain Up to 15HP
    • Three Piece Kit
    • Brilliantly Polished Finish
    • Fits Late 2001 to 2004 GT
    Gain 15HP. Improve throttle response and add power throughout your RPM range by reducing the amount of power you're losing to your accessories. And best of all, you don't have to sacrifice your A/C or charging performance - you can free up as much as 15HP with a set of BBK underdrive pulleys for your GT without negatively affecting your Mustang's ability to keep you cool.

    Premium Quality. Made of aircraft quality aluminum alloy, these BBK aluminum pulleys won't weigh you down.

    Hand Polished. The brilliant polished finish of these underdrive pulleys will give your engine bay a high performance look.

    Easy Installation. This BBK Underdrive Pulley kit installs quickly and easily in under 2 hours with no modifications required.

    Application. These BBK underdrive pullies are designed to fit the Late 2001 to 2004 GT Mustangs with the short water pump pulley with a bowed in face. Re-uses factory serpentine belt.

    Technical Note. Midway through the production run for the 2001 model year Ford changed the design of the water pump on the 4.6L engine. The older style pump produced from 1996 to mid 2001 had a longer shaft. In January of 2001 the design of the pump was changed to a shorter shaft. This necessitated a change in the design of the pump pulley.

    Click here to see pictures of the different pulley styles.

    Fitment: 2001 2002 2003 2004 Details

    MPN# 1559

    CA Residents: WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov

    What's in the Box
    • (1) Water pump pulley
    • (1) Alternator pulley
    • (1) Crank pulley
    Installation Info
    Tech Specs
    UnderDrive Pulley Specifications
    Year/Model: Late 2001-2004 GT Manufacturer: BBK
    Material: Aluminum Finish: Polished
    Crank Pulley: Piggyback SFI Certified: No
    Will it fit my Mustang?

      Customer Photos (12) Submit Your Photo

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        Questions & Answers (12)

        5 Top Rated Questions

        I see in reviews people are saying this is a piggy back system. What does that mean

        • The crank pulley in this kit will reuse your existing harmonic balancer.

        Helpful (1)

        Will the stock size belt work?

        • These BBK Underdrive Pulleys do not require an aftermarket belt size and will work with the factory belt size.

        Helpful (1)

        What is the difference from the bbk pulleys and the sr peformance ?

        • The only real difference between the BBK and the SR Performance underdrive pulleys is their appearance. They are the same size, built of similar metals and have the same functions. The BBK is a polished finish whereas the SR Performance is of a black finish.

        Helpful (1)

        I lost my spacers is there somewhere I can get replacement spacers

        • We recommend contacting BBK directly for a replacement spacer for proper installation of the BBK Underdrive Pulleys.

        Helpful (0)

        Can I use these with my V3 supercharger?

        • Underdrive pulleys, such as the BBK Underdrive Pulleys should not be used with a supercharger, as this will adversely effect boost.

        Helpful (0)
        Post Your Question
        7 More Questions
        how would these pulleys affect boost from procharger 1 answer
        I bought these from a app and it didn't come with some of the bolts and rings and washers where could I get replacement set without buying a whole new pulley set? 1 answer
        Will this work with a 2004 Mustang V6? 1 answer
        Does these fit on 03 mach 1??? 1 answer
        Does this require a tune? 1 answer
        will I need to upgrade the alternator for proper charging and upgrade to e to a different fan for cooling? thank John k 1 answer
        can I put this on my stock 03 mustang gt? 2 answers

          Customer Reviews (42) Write a Review

          Overall Rating 4.6

          out of 5 stars

          Installation Time:Afternoon

          Installation Cost:$100-$250

          • Performance Gain 4.428571 4.4
          • Fit 4.761905 4.8



          • 2/5

            February 07, 2019

            Not worth it

            This is a piggy back system I don’t like the way it all sets up I returned the bank and got the steeda underdrive pully art much better set up and great fit

            JasonH

            Year: 2003 Submodel: GT

            Helpful (3)

          • 5/5

            August 16, 2018

            Pulleys

            I just really like them and looks great on! I would recommend them to all my friends! And where easy to install

            JohnH

            Year: 2001 Submodel: GT

            Helpful (6)

          • 5/5

            Installation Time: Less than 1 Hour

            March 22, 2018

            Performance Gain

            perfect Fit Lite Weight Minutes to install fast delivery.

            RobertR

            Year: 2004 Submodel: GT

            Helpful (6)

          • 5/5

            Installation Time: Less than 1 Hour

            March 13, 2018

            Awesome

            I could tell a difference right away!!, i highly recommend this product you will gain some hp

            NiltonS

            Year: 2003 Submodel: GT

            Helpful (5)

          • 2/5

            Installation Time: Afternoon

            October 31, 2017

            Bbk

            Terrible product! Install directions TERRIBLE! The piggy back set up is just ridiculous anyways! It looks ridiculous also! Gave me check engine light for random misfires. Returned the stock the light went off.

            AmandaN

            Year: 2004 Submodel: GT

            Helpful (9)

          • 5/5

            July 12, 2017

            Undersrive pullies

            Underdorve pullies were easy and great . You could feel the difference and the Rpms go up way faster . Just the think that bothers me about this site is I can't finish my project car without these parts being out of stock AM has to have a date when there gonna be having them but they don't . Just one problem i have about this site other than that its the best site for mustang parts and easy to find

            LeonelP

            Year: 2003 Submodel: GT

            Helpful (7)

          • 5/5

            Installation Time: Afternoon

            July 07, 2017

            Nice upgrade

            Easy install and perfect fit. Not sure about any power gains, since I did a lot of upgrades at once. Installed over a year ago and still working great.

            LSUT1GR

            Year: 2004 Submodel: GT

            Helpful (6)

          • 4/5

            Installation Time: Less than 1 Hour

            July 05, 2017

            Underdrive pulleys

            Great look and a decent performance gain only complaint is if you over tighten the harmonic balancer the slightest bit it will strip due to it being a cheaper aluminum.

            John

            Year: 2003 Submodel: GT

            Helpful (6)

          • 3/5

            Installation Time: Less than 1 Hour

            July 02, 2017

            bbk underdrive

            took about 45 min to install. first couple of days they were great now at idle the car vibrates a lot. not sure if the piggy back has to do with anything but i should've gone with the Steeda ones.

            joshm

            Year: 2002 Submodel: GT

            Helpful (6)

          • 5/5

            Installation Time: Less than 1 Hour

            June 23, 2017

            Priced Right

            Easy to install. You do have to install your harmonic balancer to the new crank pulley, but its a simple process and a money saver.

            BP55

            Year: 2004 Submodel: GT

            Helpful (7)

          • 5/5

            Installation Time: Less than 1 Hour

            April 14, 2017

            Everyone needs these

            I've bought these for two different generations of Stangs (92 and 2000). The 92 Fox absolutely pinned you to the seat with these. It would leave two black marks when you hit passing gear. No matter how fast you were going. On the interstate I would tell my passengers to watch the cars around and behind us and then floor it. It would appear that everyone around me slammed on their brakes, really. The 2000 was pushed over the 350 hp mark with these. The only upgrade that was obviously added. The others add-ons were hardly noticeable.

            GeronimoH

            Year: 2000 Submodel: GT

            Helpful (9)

          • 5/5

            March 27, 2017

            Bbk

            Awsome fit well read instructions use factory pulley aswell smooth install would recommend

            MichaelP

            Year: 2002 Submodel: GT

            Helpful (7)

          • 5/5

            March 15, 2017

            Pulleys

            Loving my new up grades to my 03 mustang gt. Recently bought the cams for my car also.

            03mustang

            Year: 2003 Submodel: GT

            Helpful (7)

          • 5/5

            August 16, 2016

            Great product

            Love the pulleys I can blow my air and not lose any power

            Trey

            Year: 2004 Submodel: GT

            Helpful (8)

          • 5/5

            Installation Time: Shop Install

            July 21, 2015

            They look awesome

            I had these pulleys installed, at the same time, with a few other mods. I actually went to my local Ford dealer; nothing beats a professional job and they stand behind their work 100....(added bonus I got to test drive the 2015 GT, with performance package:) ). they look great, I can definitely feel more power and much better throttle response, especially over 3000 rpms but..... it might just be the 410 gears I also added at the same time....

            yellow03GT

            Year: 2003 Submodel: GT Montreal

            Helpful (9)

          • 5/5

            Installation Time: Afternoon

            May 13, 2014

            Money well spent

            I attempted this project myself, I'm not a tech, but I am a service advisor at a local chain repair shop so I had help when I needed it. The alternator and water pump pulley came off no problem, with the crank pulley I had a little help from a tech. All 3 pulleys fit perfectly and look awesome under the hood. Total time for install was about 2 hours. Engine seems to rev up quicker, can't wait to get down to the drag strip. Thanks to AM for awesome website!! Easy to navigate and full of information.

            chaz1974

            Year: 2002 Submodel: GT London, ON, Canada

            Helpful (7)

          • 5/5

            Installation Time: Shop Install

            Installation Cost: $100-$250

            March 16, 2014

            great response

            I really noticed the throttle response and pretty descent acceleration. Looks awsome, worth the price.

            Turtlemound32

            Year: 2003 Submodel: GT Memphis, TN, USA

            Helpful (7)

          • 5/5

            Installation Time: Afternoon

            February 15, 2014

            be prepared

            I got these pulleys because i already had to replace my belt tensioner and idler pulley, so figured i might as well do an upgrade while I'm at it. and for a fairly inexperienced car guy the install was pretty straight forward, when taking off the stock crank pulley you WILL NEED A PULLEY PULLER, AND A BIG BREAKER BAR. took a lot more force to get the bolt out than i had anticipated, great product though! may have gone with the steeda kit if i had realized it was a piggy back style kit, but none the less this will work perfectly on your car, i am 100% satisfied

            AJ04

            Year: 2004 Submodel: GT Dallas, TX

            Helpful (7)

          • 4/5

            Installation Time: Afternoon

            January 29, 2014

            Install was a snap. Worry Free

            Everything fits/matches up really well. Uses stock belt size. There's no issues with charging due to the pulley. I have a stock sound system, stock alternator, and factory spec battery. Even with headlights on and radio blasting, there no dip in voltage. So no worries there. No noticeable coolant temp increase either. Took about 1 1/2 hr to install at a nice and easy pace. Remember guys, "Slow is smooth and smooth is fast"

            bstone244

            Year: 2004 Submodel: GT York, PA, USA

            Helpful (7)

          • 5/5

            Installation Time: Afternoon

            September 28, 2013

            great product!

            I ordered these pulleys from AM on a monday and got them on a wednesday. the only hard part of the installation was getting the old pulleys off. Other than that its good to go and I noticed a good gain in tq and hp. I would highly recommend this product to anybody

            Jmont

            Year: 2003 Submodel: GT

            Helpful (7)

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