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1979-93 Mustang ASP Aluminum Underdrive Pulley Kit by ASP

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1979-93 Mustang ASP Aluminum Underdrive Pulley Kit
1979-93 Mustang ASP Aluminum Underdrive Pulley Kit
1979-95 Mustang How to Measure Serpentine Belt Length (5.0)
How To Remove & Install Pulleys On Your Fox Body Mustang (79-93)

Add horsepower and style to your Fox Body with these 79-93 Mustang 5.0 Satin Aluminum Underdrive Pulleys.

Item #ASP-824125
MPN# 824125

Everyday Low Price: $159.99

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  • Increase Horsepower
  • Added Detail


  • Satin or "Clear" Finish Pulleys
  • Billet Aluminum Construction
  • 25% Underdrive Crank
  • 15% underdrive Water Pump
  • 950 RPM Full Charge
  • Installs with simple hand tools

 What's in the Box

  • (1) 25% Crank Pulley
  • (1) 15% Water Pump Pulley
  • (1) 2.47" Alternator Pulley

ASP Aluminum Underdrive Pulley Kit
Underdrive pulley systems increase engine horsepower by reducing the amount of power required to drive external engine accessories. For example, the alternator, power steering, water pump and air compressor rob horsepower from the engine. By replacing factory-sized crank and accessory drive pulleys with a resized pulley, the accessories are slowed, resulting in more horsepower available to the drive wheels. Typically, a set of Auto Specialties street pulleys will increase horsepower by 12-15, and increase mileage by 2 to 3 MPG. All pulleys are manufactured from Billet Steel or Aluminum, exceeding factory quality.

Product Note
Due to the difference in diameter from the stock Mustang pullies, the alternator and charging system may need to be upgraded if you have a large stereo system.

Pulley Measurements
  • Alternator Pulley - 2.47"
  • Crank Pulley - 4.625"
  • Water Pump Pulley - 5.438"
  • Fits 1979-1993 V8 Mustangs

  • The alternator pulley in this kit will only work with the stock 75 amp alternator. The underdrive alternator pulley will NOT work on 3g upgrades.

    ASP / Performance Machine Works Warranty - Click Here

    • Ford Mustang - 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993

    Check out our YouTube channel for even more tech tips, installation videos, how-tos, and more. The best place to go for anything Mustang related!

  • How To Remove & Install Fox Body Pulleys | 79-93 Mustang

    Check out 5.0 Resto's Fox Body pulley removal and installation steps! This applies to 1979-93 Mustangs and they are sure to make it as easy as possible! more

    Read more: fox body , 79 93 mustang , cobra

    Posted on 10/8/2020

  • California Residents:
    Prop 65 Warning SignWARNING: Cancer and Reproductive Harm- www.P65Warnings.ca.gov

    About This Brand

    ASP - Quality. Performance. Products.
    ASP is one of the industry's leading producers of Mustang performance pulleys. Since 1988 ASP has been machining underdrive pulleys in house to give you the most performance for your Mustang. Each pulley goes through a CNC lathe for accurate measuring and cutting. The pulleys go through 2 cycles and a quality check to ensure each part is perfect before it leaves out of the door.

    Look for Similar Items by Category

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