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BBK Underdrive Pulleys (Late 01-04 GT)

Market Price $181.99 You Save 12% ($22.00)
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$159.99

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  • Item 56008
  • MPN# 1559

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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

    CA Residents: Warning: California's Proposition 65

    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?

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    Questions & Answers (10)

    5 Top Rated Questions

    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)

    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 (0)

    how would these pulleys affect boost from procharger

    • We do not recommend using the BBK Underdrive Pulleys, or any other underdrive pulleys on a supercharged setup, as this will reduce boost, causing a loss in horsepower and torque, as the supercharger kits are designed around stock pulley diameters.

    Helpful (0)

    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?

    • Unfortunately, we only sell the full set. I would recommend contacting BBK directly.

    Helpful (0)

    Will this work with a 2004 Mustang V6?

    • These BBK Underdrive Pulleys are designed specifically for the GT, and would not fit the V6.

    Helpful (0)
    Post Your Question
    5 More Questions
    What is the difference from the bbk pulleys and the sr peformance ? 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

    People Who Bought This Item Also Bought

    Customer Reviews (41) Write a Review

    Overall Rating 4.7

    out of 5 stars

    Installation Time:Afternoon

    Installation Cost:$100-$250

    • Performance Gain 4.6 4.6
    • Fit 4.95 5.0



    • 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 (0)

    • 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 (3)

    • 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 (3)

    • 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 (4)

    • 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 (3)

    • 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 (3)

    • 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 (3)

    • 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 (3)

    • 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 (4)

    • 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.

      SteveH

      Year: 2000 Submodel: GT

      Helpful (5)

    • 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 (3)

    • 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 (3)

    • 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 (4)

    • 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 (6)

    • 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 (4)

    • 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 (4)

    • 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 (4)

    • 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 (3)

    • 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 (4)

    • 5/5

      Installation Time: Afternoon

      November 11, 2012

      Excellent with a fresh air intake.

      We went on a road trip to Boston. The trip was just over 3800m. I averaged 20.3 mpg. This year we went on a roadtrip to Yellowstone, about 5300m. I averaged 23.04 mpg. The changes in the car between the trips where a fresh air intake, under drive pulleys, and a 3 tune chip. The tune made the least impact in fuel economy. I used the street tune for the trip out on I94 and the stock tune on the I90 heading home. They came back as 24.52 and 24.14 repectively. The flat highway average for the whole trip is 24.35. Not too much difference but it is there. The intake and pulleys took the mileage up over 13%. I think that is pretty impressive. The car is a ragtop. The coupe will do better. On the performance end of things the results are the same. There is a huge difference in driveability. Both the intake and the pulleys changed the way the car performs coming off the line. They made the car feel lighter and stronger. The difference with the chip is there but shows up more on the track performance with the performance 87 and race 91 tunes. The intake and pulleys are must haves, the chip is a nice to have.

      Johns2004GT

      Year: 2004 Submodel: GT Ottawa, Ontario, Canada

      Helpful (6)

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