Talk to a Mustang Expert
1-888-332-7930
M-F 9-9,Sat 9-5:30,Sun 12-4 ET

Free Shipping on Everything. Seriously. Details

Steeda Underdrive Pulleys (Late 01-04 GT)

71 Reviews
Our Price

$239.95

  • Item #16090
  • MPN# 701-0003

  • Market Price $264.99
  • You Save 9% ($25.04)
In Stock Ships same business day.
Free Shipping on Everything
Customer Photos
Features
  • 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
Description
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 stock 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 stock 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

Won't fit? Add an exception

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?
  • GT - 01, 02, 03, 04

Fits Mid 2001 to 2004 GT's Only

Most Helpful Reviews

5/5
highly impressed

super easy to install, than again i am a tech, but would be super easy for anyone with proper tools, aka an impact and pully remover. i was very impressed with the mid range power gain. low end torque ...

Read More
Helpful (11)

5/5
Great product

Pretty simple instructions, easy install, and great gains from it through mid rpm range and higher. I drive an auto and now it feels like it has so much more left at the higher rpms. And as always American ...

Read More
Helpful (10)

Read All 71 Reviews
Overall Rating 4.7 out of 5 stars

Customer Photos (10) View All Photos

You Might Also Like

5 Questions / 6 Answers

Ask a Question

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.

MoeAli Year: 2004 Model: GT

  • 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.

    Best Answer

    miami01 Year: 1997 Model: GT Top 100 Contributor

    Good Answer (2)

Show 4 more answers Question Resolved

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?

VertMach1000 Year: 2003 Model: GT

  • I would say you should get an upgraded alternator. The mach 1000 takes a lot of electricity to power it with peak power of 1140 watts will drain batteries quickly.

    SharkWeek Year: 2004 Model: GT

    Good Answer (0)

Question Resolved

Will the underdrive pulleys work with a mustang that has the mach 1000 radio option?

VertMach1000 Year: 2003 Model: GT

More Products You Might Like

Customer Reviews (71) Write a Review

Overall Rating 4.7

out of 5 stars

Installation Time:Afternoon

Installation Cost:$100-$250

  • Performance Gain 4.038462 4.0
  • Fit 4.961538 5.0
  • Bang For Your Buck 4.592593 4.6



  • 5/5

    August 17, 2010

    highly impressed

    super easy to install, than again i am a tech, but would be super easy for anyone with proper tools, aka an impact and pully remover. i was very impressed with the mid range power gain. low end torque was increased some and also with throttle responce, but the mid range power was pretty noticable, i would definantly reccomend this to any mustang owner inless you plan to put boost to your motor because you wont be able to run as much psi with underdrives. thanks AM

    AJ

    Helpful (11) (0)

  • 5/5

    July 04, 2010

    Great product

    Pretty simple instructions, easy install, and great gains from it through mid rpm range and higher. I drive an auto and now it feels like it has so much more left at the higher rpms. And as always American Muscle is the best!

    Blake C.

    Helpful (10) (1)

  • 5/5

    July 21, 2008

    Definitely worth it

    These pulleys were easy to put on. The only challenge is taking the old pulleys off. Heres a tip, remove the radiator overflow tank (just remove 3 nuts and swivel off to the side) and the fan ( 2 bolts, and a little wiggling) and use an impact wrench on the crank pulley as well as the alternator.

    Stephen

    Helpful (7) (0)

  • 2/5

    Installation Time: Afternoon

    September 23, 2011

    Steeda Good,Pullys bad

    I bought theses pullys and AM shipped them very fast. The pullys do give good HP gains. My problem was that I had to get a new alternator. So paying 200 for the pullys and another 200 for an alternator is not worth the power gains. AM is a great place to shop for your stang I just dont want people to have to go throught what I did for these.

    Top 500 Contributor

    Griffin

    Year: 2003 Model: GT Driving Style: Daily Driver 'Stangs I have owned: 1

    Helpful (8) (1)

  • 5/5

    September 29, 2010

    steeda underdrive Pullies

    Great product,didn't think it would make a big difference but gained 10 kms per hr on 1/4 mile.

    Clayton Hopkins

    Driving Style: Street / Strip

    Helpful (6) (0)

  • 5/5

    January 30, 2010

    Quick RPM Jump

    Hi guyz this is my very first MOD for my 01 GT. I dont know much about these cars yet, but I managed to install these Pulleys easily. Right after installation RPM jumps quick and car is more responsive. So far my AC/Power Steering and all the other accessories work fine. There is a noticable gain in acceleration, BUT NOT A LOT.

    SOHAIL

    Year: 2001 Model: GT

    Helpful (7) (1)

  • 5/5

    Installation Time: Less than 1 Hour

    June 11, 2012

    Smart Money on this product! Do not go with Piggy back system

    I gained approximately 2 mpg and I would say 10 hp. The car revs quicker. Excellent quality and everything fit perfectly. The new belt rides smoothly right down the center. I would not waste my time on the piggyback aluminum products. This crank pulley is built with the harmonic balancer as one unit. Ford helped Steeda design this setup. Read the instructions, have all the right tools and be able to work from under the vehicle.

    re123

    Year: 2003 Model: GT Driving Style: Daily Driver 'Stangs I have owned: 4 SoCal

    Helpful (3) (0)

  • 5/5

    May 10, 2010

    Must Have

    I never write reviews. The alternator was hard to get pulley off of. The performance is better than expected. It is worth it in time and effort. I can't stop driving her now. My 04GT is smooth and as silk. Have someone along during replacement to assist.

    Big AL

    Year: 2004 Model: GT

    Helpful (4) (1)

  • 5/5

    February 09, 2010

    Great Product

    These pullys were a great addition to my 03 GT didnt see much of a gain in power but are a very goodproduct. The best part is the crank pully isnt a piggyback system like other kits.

    Andrew

    Year: 2003 Model: GT

    Helpful (5) (2)

  • 3/5

    May 12, 2011

    Steeda Underdrive Pulleys, 04 GT

    The product arrived promptly, looked like the high quality product I would expect from Steeda and installation was easy. I immediately noticed that when idling in drive and particularly when the ac is on the lights dim. It did not take much of a raise in RPM to brighten them back up but it was quite noticeable. I replaced the Steeda alternator pulley with the OEM pulley and this helped but there is still a slight dimming in lighting when at idle and the automatic transmission is in drive. American Muscle told me my battery was probably weak. I have not had any previous issues with my battery or charging system but am currently trying to determine my next move. I hope I do not have to purchase a higher amperage alternator because of my choice to use underdrive pulleys.

    Douglas Lance

    Year: 2004 Model: GT Driving Style: Daily Driver

    Helpful (6) (4)

Related Categories