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SR Performance Underdrive Pulleys - Black Aluminum (86-93 5.0L)

Item 525569
Market Price $108.99 You Save 17% ($18.00)
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      Review & Installation Video

      These are the SR Performance underdrive pulleys for '86 to '93 5-liter Mustangs. You're gonna wanna check out the SR Performance underdrive pulleys if you're looking for a set of pulleys to free up a touch of horsepower in a fast, easy, and very affordable way. The SR Performance pulleys cost the least out of any pulley option, so they're currently the most budget-friendly. Now the theory behind underdrive pulleys is that factory pulleys require a lot of energy. A set of lightweight aluminum pulleys like these here, reduce the amount of parasitic drivetrain loss by cutting down on the amount of power it takes to run the accessories, like your water pump, your alternator, and the AC compressor, and some people mentioned noticing a difference after installing these. Underdrive pulleys are only a good idea if you plan on keeping your car naturally aspirated, so just keep that in mind when you figure out your future plans. The install for these is gonna be an easy one out of three wrenches in the difficulty meter, and you can plan on spending about two hours to get the install done. So the engine uses its own power to rotate the serpentine belt starting at the crankshaft. This pulley then uses the engine's power to rotate the rest of the pulleys. So when you reduce the size of the crankshaft pulley, it's gonna require less energy to rotate the accessories. The pulleys in this set are lightweight aluminum, which means that they'll require even less energy to rotate. This set has a powder-coated black finish, but SR Performance also sells a set that's polished if you like the look of those instead. This kit's gonna include the crank pulley, the water pump pulley, and the alternator pulley, as well as the hardware to get these installed. The nice thing about these is that you'll be able to free up the power that the engine's currently using to rotate these pulleys, but you won't sacrifice the effectiveness of the accessories. So your water pump and your alternator will still function perfectly, they'll just require less power from the engine to operate. The only time that you can see issues is if you have an aftermarket sound system and an upgraded alternator. These items are more taxing on the car system and will require more work from the alternator. So if that's the case, I would recommend steering away from underdrive pulleys. But for those of you that don't have that kinda setup, these will reuse the stock belt so you won't have to get a different size belt which will make it easier when you need to replace your belt. When it comes to fitment, just make sure you're shopping for the correct thing here. These are underdrive pulleys for the '86 to '93 5-liter. And this kit is made to reuse the stock belt and assumes that everything is still stock. If you've eliminated anything, like your smog pump or your AC, you will have to do some of your own engineering here as far as the belt sizes go. But if you're still stuck and haven't deleted your smog pump or your air conditioning, you'll reuse the stock size belt. As far as price, you're looking at right about $100 for this kit. This is one of the most affordable pulley kits currently at this time. If you wanted to spend less, SR Performance also sells a black steel set that's gonna weigh a little bit more, but it will cost less. Don't forget you do have the choice of the SR Performance polish pulley kit if you didn't want the black set, or you have the choice of another brand like BBK or Steeda. Just know that they won't be as price-friendly as this kit is. The install here is easy, and I'm gonna call it a one outta three wrenches in the difficulty meter. You're gonna expect to spend about two hours getting the install done, and you'll just need some basic hand tools to get the job done, which includes a socket set. You should loosen the knot in the center of the alternator prior to removing the belt and loosen the water pump bolts and the crank pulley bolts as well. You'll need to release the tension on your serpentine belt and set it aside. From there, it's just a matter of unbolting the factory pulleys and replacing them with the underdrive pulleys from the SR Performance kit. Once they're bolted in, release the tension pulley again and put the serpentine belt back on. You'll need to make sure that it's on properly by following the diagram that's usually located on the radiator cover. Wrapping things up here with the SR Performance underdrive pulleys, these pulleys are for the '86 to '93 5-liter Mustang. And you can check them out more online right here at

      Product Information

      Features, Description, Reviews, Q&A, Specs & Installation


      • Free Up Horsepower
      • Complete 3 Piece Kit
      • Durable, Lightweight Aluminum
      • Black Powder Coated Finish
      • Premium Quality Construction
      • Fits 1986-1993 5.0L V8 Mustangs


      Free Up Horsepower. A set of SR Performance Underdrive Pulleys reduce parasitic drivetrain loss by cutting down the amount of power your accessories take up, these underdrive pulleys will free up 10+ horsepower, without sacrificing cooling and charging functionality of your Pony.

      Premium Quality Construction. CNC-machined from lightweight aircraft grade quality aluminum alloy for strength and durability, these SR Performance pulleys feature a gloss black powder coated finish for aggressive good looks and long lasting corrosion resistance.

      Easy Installation. These SR Performance Mustang Underdrive Pulleys installs quickly and easily in under 2 hours with no modifications required.

      Application. This SR Performance 3-Piece Black Aluminum Underdrive Pulley Kit is designed for use on 1986 to 1993 Ford Mustangs equipped with the iconic push rod 5.0L V8 engine, including the LX 5.0, GT and SVT Cobra models. Reuses stock belt.

      SR Performance

      Fitment: 1986 1987 1988 1989 1990 1991 1992 1993 Details

      MPN# 525569

      CA Residents: WARNING: Cancer and Reproductive Harm -


      Customer Reviews (67)

      Write a Review

      Ratings Summary

      4.7 out of 5 overall rating from 67 customers

      Installation Time: Less than 1 Hour

      Installation Cost: 0-$100

      • January 28, 2020

        Review shared from SR Performance Underdrive Pulleys - Polished (86-93 5.0L)

        4 1991 LX - Bkroner Installation Time: Less than 1 Hour

        Downdrive pulley's

        The pulley for my alternator would not fit to my 110 Amp alternator. The other two pulley"s were the exact thing I needed. As far as performance I am not sure yet I am still working on car to be road ready.

        Helpful (0)
      • December 30, 2019

        Review shared from SR Performance Underdrive Pulleys - Polished (86-93 5.0L)

        5 1988 GT - Zach88 Installation Time: Less than 1 Hour

        Well worth it

        Great product 100 worth it. They look good and are perfectly quiet. They make the make the engine a lot happier to rev and as for cooling stays perfectly fine but lights do dim a little at idle but not a big deal in my opinion

        Helpful (0)
      • December 18, 2019

        Review shared from SR Performance Underdrive Pulleys - Polished (86-93 5.0L)

        5 1992 GT - MatthewP Installation Time: Less than 1 Hour

        Great pulleys for the price!

        Great pulleys. They look good and are priced good. A on another well priced well made item.

        Helpful (0)
      • December 16, 2019

        Review shared from SR Performance Underdrive Pulleys - Polished (86-93 5.0L)

        5 1992 GT - Restomod65 Installation Time: Less than 1 Hour


        Looks very good can’t feel power increase but for the price the look is worth it

        Helpful (0)
      • December 15, 2019

        Review shared from SR Performance Underdrive Pulleys - Polished (86-93 5.0L)

        5 1993 LX - navydoc


        Well package and good quality part this will give your 5.0L a nice look under the hood .

        Helpful (0)
      • October 20, 2019

        Review shared from SR Performance Underdrive Pulleys - Polished (86-93 5.0L)

        5 1988 GT - RickTamiS Installation Time: Afternoon

        A little bling

        This is a great set of underdrive pulleys with excellent manufacturing quality. The stock water pump pulley took a bit of persuasion to remove but once that was off the installation went quite easily. It is hard to be sure but the car did feel a bit more responsive to throttle input and peppy after the installation.

        Helpful (0)
      • August 10, 2019

        5 1991 LX - Turbofox92 Installation Time: Less than 1 Hour

        Their black and lightweight

        I wanted a set of black aluminum pulleys and American muscle had exactly what I was looking for...AWESOME

        Helpful (0)
      • June 13, 2019

        Review shared from SR Performance Underdrive Pulleys - Polished (86-93 5.0L)

        5 1993 GT - Jerrick Installation Time: Less than 1 Hour

        Great Product

        Everything bolt as it should. the parts feels and looks quality made.

        Helpful (0)
      • May 31, 2019

        4 1993 GT - Slow5Oh Installation Time: Less than 1 Hour


        Had some scuffs on the alternator pulley, but all in all good quality and fast shipping.

        Helpful (0)
      • May 08, 2019

        5 1993 GT - Trigr9 Installation Time: Less than 1 Hour

        Nice product!

        Went on with no issues and reused the factory belt

        Helpful (1)

      Questions & Answers (9 answers)

      5 Top Rated Questions

      Will this work on my 351W

      • The SR Performance Underdrive Pulleys are designed for the 5.0L 302 blocks. They are not designed to work with the 5.8L 351W.

      Helpful (1)

      Hi so the pulleys will get you 10/15 more horse only if you do other mods?? Is this correct I want to get me a set . My mods are shorty headers h- pipe a set of flow masters right now I want to put on the pulleys and a different mass air unit. I have a speed density system I am going to keep the SD system. Then possibly different upper and lower intake. Is it worth it to to buy and install the pulleys with these few mods? Will I get the 10/15 horse? Even if I don't go with the upper and lower intakes? Thanks much Mike

      With the SR pulleys will the car full charge at idle?

      • These SR Performance Underdrive Pulleys will free up 10+ horsepower, without sacrificing cooling and charging functionality of your Pony.

      Helpful (0)

      you usually need a different belt with under drive pulleys, what is difference with the SR pulleys since it reuses the stock belt? Thanks -Will

      • The SR Performance Underdrive Pulleys are sized to be able to reuse the OEM belt. This is true of both the BBK and SR underdrive pulleys we offer.

      Helpful (0)

      will these pullies work with a car thea has an a/c delete?

      • Yes, these Pulleys would work even if you have deleted the A/C.

      Helpful (0)
      Post Your Question
      4 More Questions
      i have an a/c delete on my 92 gt are these ok to install with that mod in place? 1 answer
      Has the issue with the crank bolts been resolved yet? I want to order this kit, but with the complaints about the crank bolts being the wrong size has put me off. The last thing I want to do after I get everything apart is to have to stop what I'm doing and go buy the correct ones. 1 answer
      Can you use the stock size serpentine belt? A different review said the belt needs to be an inch bigger, is this true? 1 answer
      What are the dimensions of the pulleys? Diameter specifically 1 answer

      Installation & What's in the Box

      Installation Info

      What's in the Box

      • (1) water pump pulley
      • (1) alternator pulley
      • (1) crank pulley
      • (4) bolts

      Tech Specs

      UnderDrive Pulley Specifications
      Year/Model:1986-1993 5.0L V8 Manufacture:SR Performance
      Material:Aluminum Finish:Black Powder Coated
      Crank Pulley: Piggyback SFI Certified:No

      Will It Fit My Mustang

      • Cobra - 93
      • Cobra R - 93
      • GT - 87, 88, 89, 90, 91, 92, 93
      • LX - 87, 88, 89, 90, 91, 92, 93
      • Other - 86

      Fits 5.0L V8's Only

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