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Steeda Underdrive Pulleys (Late 01-04 GT)

AmericanMuscle no longer carries the Steeda Underdrive Pulleys (Late 01-04 GT). Please check out 1999-2004 Mustang Underdrive Pulleys for an updated selection.
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Features & Details

  • SFI Approved
  • 8 - 10 RWHP Recovery
  • Improves Fuel Economy
  • 25% Reduction in Parasitic Accessory Drag
  • Exceeds OEM Material Specifications
  • Fits Late 2001 to 2004 GT Mustangs
Regain Lost Power. Get back the power and torque your belt-driven accessories steal. As hard as it may be to believe, you can regain from 8 to 10 "free" horsepower with Steeda's underdrive pulleys. These pulleys reduce engine parasitic drag from your accessories by about 25% and even improve fuel economy.

Superior Materials. Steeda underdrive pulleys are manufactured from nodular iron, and far exceed the quality of the factory pulleys. The one-piece crankshaft pulley uses a high-tech injection molded bonded rubber damper, making it far more durable than other manufactures "piggyback style" underdrive pulleys.

SFI Approved. Steeda underdrive pulleys are SFI approved for use by all major race sanctioning bodies.

Application. These Steeda Underdrive Pulleys are specifically designed for use on the Late 2001 to 2004 4.6L V8 GT Mustangs.Re-uses factory serpentine belt.

Note: Coupon codes cannot be applied to this product.



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# 701-0003

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

What's in the Box
Hardware included:
  • Crankshaft pulley
  • Water pump pulley
  • Alternator pulley
  • Crankshaft pulley starter bolt*
* must be removed after seating pulley!
Installation Info
Tech Specs
UnderDrive Pulley Specifications
Year/Model: Late 01-04 GT Manufacture: Steeda
Material: Steel Finish: Black
Crank Pulley: One Piece Crank SFI Certifited: Yes
Will it fit my Mustang?

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Questions & Answers (10)

5 Top Rated Questions

Can they be used with any belt driven supercharger

  • The Steeda Underdrive Pulleys will work on a late 01-04 GT with a supercharger.

Helpful (1)

Will this work with pro charged mustang?

  • The Steeda Underdrive Pulleys will work with a Procharged Mustang.

Helpful (1)

Do I need to buy a more powerful alternator when fitting these pulley's as some of the comments suggest? I recently bought a remanufactured stock alternator and I want to know if that is good enough for this pulley.

  • They will work great if you don't have a big sound system. The only time they will show a low charge is at idle,But if your alternator is working properly you will not have a problem.

Helpful (1) Show 4 more answers

Will the factory serpentine belt work with these? Or will i need a different length belt?

  • The Steeda Underdrive Pulleys will re use the factory Serpentine Belt.

Helpful (0)

Would these pulleys work well with a cammed 2v mustaqng?

  • The Steeda Underdrive Pulleys will work well with a cammed 2v yes.

Helpful (0)
Post Your Question
5 More Questions
What is the diameter of the alt and water pump pulley? I understand it is difficult to see in photos but they look simliar to stock pulleys Can't be a big change if the stock belt is re-used unless the auto tensioner is making up for the change. I know it doesn't take a big size reduction to make small gains but I am curious of the stock diameter vs Bbk's diameter?!?! 1 answer
will these fit my 4.6l 2004 crown victoria. im aware that most mustang gt parts are compatible with crown victorias right? 1 answer
Will this fit my 01 Bullitt? 1 answer
Will the underdrive pulleys work with a mustang that has the mach 1000 radio option? 1 answer
Will this work with a Mach 1000 radio option? My 2003 GT came with a Mach 1000 radio option. Will using the underdrive pulleys affect the radio and other electrical needs of the car adversely? 1 answer

Recommended For You

Customer Reviews (94) Write a Review

Overall Rating 4.7

out of 5 stars

Installation Time:Afternoon

Installation Cost:$100-$250

  • Performance Gain 4.163265 4.2
  • Fit 4.938776 4.9



  • 5/5

    Installation Time: Less than 1 Hour

    March 14, 2019

    Awesomeness

    Very very pleased with my underdrive pulley thank you American muscle.

    Robert

    Year: 2002 Submodel: GT

    Helpful (0)

  • 5/5

    Installation Time: Afternoon

    March 12, 2019

    Good bolt on mod

    These gave me some noticeable down low torque that i lost after installing bbk long tube headers. Cant hook from a dig without warming up the tires now.

    JeffreyR

    Year: 2001 Submodel: GT

    Helpful (0)

  • 5/5

    Installation Time: Shop Install

    Installation Cost: $100-$250

    November 29, 2018

    Steeda Underdrive Pulleys

    Have had a lot of mods done. My point being is go with Steeda when it comes to the Underdrive Pulleys and not BBK. The BBK which I purchased before was a "piggyback setup" which is completely ignorant on BBK patent of their engineering of their Underdrive Pulleys set up. The crank pulley should be (ONE) Pulley, not another pulley "bolted" to the original stick crank pulley! Makes absolutely no sense, and makes a person, me anyhow feel as though I'm using still the original "208 lb" ( figure of speech) stock crankshaft pulley so my opinion, GO WITH STEEDA UDP, BBK hire a team of different engineers who do the design work of your UDP Department.

    JoshuaN

    Year: 2004 Submodel: GT

    Helpful (3)

  • 4/5

    Installation Time: Less than 1 Hour

    September 07, 2018

    great features

    I can tell the difference when install the underdrive pulleys rpm are quicker now

    MesioM

    Year: 2002 Submodel: GT

    Helpful (1)

  • 5/5

    Installation Time: Afternoon

    September 01, 2018

    Great fit

    This is my first set of under drive pullies and the install was a breeze. I also have a custom a.c. delete. Sprayed the bolt with pb blaster for three days and nights before the install. Broke the balancer loose with a breaker bar. Great fit and I can tell the engine actually benefited from this. Also running a 180 thermostat and have had no issues with cooling or charging. Definitely recommended

    LTHL281

    Year: 2004 Submodel: GT

    Helpful (1)

  • 5/5

    Installation Time: Afternoon

    May 29, 2018

    slow down and go fast

    the pulleys look to be real good quality. They were easy enough to install except the lockwasher is too thick to go back on the alternator. No difference in charging with new pulleys and temperature of engine didn't change. The steering is a little harder when moving real slow like in parking lots.

    LyndaP

    Year: 2003 Submodel: GT

    Helpful (3)

  • 5/5

    Installation Time: Less than 1 Hour

    April 08, 2018

    STEEDA PULLEYS!

    Got my pulleys today. Packing was perfect. Looks great finish product. Will install them soon with 4.10 gears

    MustangDubai

    Year: 2004 Submodel: GT

    Helpful (3)

  • 5/5

    Installation Time: Afternoon

    April 04, 2018

    Great product.

    Installation was so easy. It took me an hour and a half. I went for a test and you can feel the power right away. I'm so happy with the way my car response for throttle.

    JoseP

    Year: 2003 Submodel: GT

    Helpful (3)

  • 5/5

    Installation Time: Less than 1 Hour

    March 22, 2018

    Steeda Underdrive Pulleys

    Noticeable better throttle response and much noticeable response on higher RPM's, bit fuel economy as-well. Overall good quality made product.

    Grant

    Year: 2004 Submodel: GT

    Helpful (3)

  • 5/5

    Installation Time: Afternoon

    October 22, 2017

    AWESOME INCREDIBLE

    Theses were way better than the BBK under drive pulleys, regarding the harmonic balancer dampener is all one unit....

    JohnY

    Year: 2004 Submodel: GT

    Helpful (3)

  • 5/5

    October 18, 2017

    good bolt on for a 5-8 hp gain

    nice product!!! easy bolt on install.....AM was great answering questions and helping with an issue I had with another product....This combined with my catback exhause and cold air intake (all purchased through AM) made a big difference in "funability"

    DavidN

    Year: 2003 Submodel: GT

    Helpful (4)

  • 5/5

    Installation Time: Less than 1 Hour

    October 07, 2017

    Nice Pulleys

    Direct replacement and well worth the money. Noticeable throttle response and mid torque pull. Make sure to get a new crankshaft harmonic balancer bolt. If your alternator has the thin nut with the lock washer i highly advise getting the flanged nut for your alternator pully to prevent stripping due to slightly thicker alternator pulley. Great buy!

    CharlesM

    Year: 2004 Submodel: GT

    Helpful (5)

  • 5/5

    Installation Time: Less than 1 Hour

    September 27, 2017

    Much better than Piggyback Pulleys

    Steeda Pulleys fit perfectly. I originally installed a set of piggyback pulleys and removed them before I started the engine. Do yourself a favor and buy these instead of the other options. The quality difference is night and day. I'm not sure about power gains since these were installed on a new motor with different cams.

    MichaelS

    Year: 2002 Submodel: GT

    Helpful (4)

  • 5/5

    Installation Time: Full Day

    September 10, 2017

    Nice product..

    First, if you don't have an impact wrench and a puller, get one as you'll need it. Also, plan on a full day to install. For the wrench to fit I had to pull the radiator. This was not a bad thing as my lower radiator hose was shot and collapsed. I went ahead and replaced the thermostat as well. The performance gain was really noticeable. Between the unrestricted hose and the pulleys, the motor revs up faster. Worth the price and effort, especially if you haven't serviced your coolant system recently.

    AlaskaStang

    Year: 2004 Submodel: GT

    Helpful (3)

  • 5/5

    Installation Time: Afternoon

    August 29, 2017

    Steeda pulleys

    Great choice. Makes the car peppy. The car revs easyier now probably more noticeable since I have a manual. Slightly harder to steer into parking spots at a idle. The car warms up slightly faster but the fan keeps up no problem. No issues with my battery got 5 year warranty on it anyways. I recommend this product. The car gets 8.8l/100k now used to be 9. I would do it again!

    Kevin

    Year: 2002 Submodel: GT

    Helpful (3)

  • 5/5

    Installation Time: Less than 1 Hour

    August 22, 2017

    Steeda Quality!

    From fit to finish- no regrets! These pulleys are as advertised!

    06Bill

    Year: 2006 Submodel: GT

    Helpful (4)

  • 5/5

    Installation Time: Afternoon

    June 27, 2017

    2004 Mustang GT with Steeda Pulleys

    Really happy with them! They look factory which is nice so people don't notice the difference. I had a mustang priority this one and did the bbk but these seem a lot higher quality. Hardest Pulley was the crank but if you have a pulley puller you will be fine. Highly recommend

    CarloJ

    Year: 2004 Submodel: GT

    Helpful (3)

  • 5/5

    Installation Time: Afternoon

    June 09, 2017

    Great Pulleys!!!

    Do not make the same mistake I did. Save your money, but these pulleys. I bought a couple of different pulleys before finding these. These are Great Quality and fit perfect with Zero deflection! A Great Job Steeda!

    AlexP

    Year: 2003 Submodel: GT

    Helpful (3)

  • 5/5

    Installation Time: Less than 1 Hour

    May 01, 2017

    Steeda!!

    can't go wrong with these. Wasn't sure it would give me noticeable gains because of what some people say on here but once installed I actually noticed a difference. Definitely worth the money!

    Kenneth

    Year: 2004 Submodel: GT

    Helpful (3)

  • 5/5

    Installation Time: Afternoon

    March 30, 2017

    Fantastic product and great quality

    Installed these on my 04 gt and it really woke up my car. Getting the crankshaft bolt off was a huge pain but once you that was off it was smoothe sailing. You will need to use a harmonic balancer puller to get the harmonic ballencer off of the crank. Great product and worth the paying a little extra for a quality product.

    Dwright

    Year: 2004 Submodel: GT

    Helpful (3)

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