(approx) 2 Hours
Light to Moderate mechanical skill required.
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 americanmuscle.com.
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Features, Description, Reviews, Q&A, Specs & Installation
Fitment: 1986 1987 1988 1989 1990 1991 1992 1993 Details
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January 28, 2020
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
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 opinionHelpful (0)
December 18, 2019
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
Looks very good can’t feel power increase but for the price the look is worth itHelpful (0)
December 15, 2019
Well package and good quality part this will give your 5.0L a nice look under the hood .Helpful (0)
October 20, 2019
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
Their black and lightweight
I wanted a set of black aluminum pulleys and American muscle had exactly what I was looking for...AWESOMEHelpful (0)
June 13, 2019
Everything bolt as it should. the parts feels and looks quality made.Helpful (0)
May 31, 2019
Had some scuffs on the alternator pulley, but all in all good quality and fast shipping.Helpful (0)
May 08, 2019
Went on with no issues and reused the factory beltHelpful (1)
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.
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.
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.
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.
Yes, you could use the SR Performance Underdrive Pulleys even if you have deleted your air conditioning.
The SR Performance Underdrive Pulleys have been corrected in all of our recent batches received from the manufacturer.
The SR Performance Underdrive Pulleys are designed for use with a stock belt length.
The alternator pulley will be about 2.5" in diameter, the crank pulley will be about 4 3/4" in diameter, and lastly, the water pump pulley will be about 5 1/4" in diameter.
(approx) 2 Hours
Light to Moderate mechanical skill required.
What's in the Box
|Year/Model:||1986-1993 5.0L V8||Manufacture:||SR Performance|
|Material:||Aluminum||Finish:||Black Powder Coated|
|Crank Pulley:||Piggyback||SFI Certified:||No|
Fits 5.0L V8's Only