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SLP Loudmouth Center/Center Shotgun Style Resonators - 2.5 in. - Pair (79-04 All)

Market Price $174.95 You Save 6% ($10.00)
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  • Item 23032
  • MPN# 31062

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Features & Details

  • Loud Aggressive Sound
  • Virtually No Restrictions for More Horsepower
  • Designed for SLP Modular Cat-Backs
  • 2.5" Inlet/Outlet Diameter
  • Hand-Polished 304 Stainless Steel
  • Sold as a Set of Two
More Power and Sound.   These SLP Loudmouth "shotgun" race resonators are designed to have virtually no exhaust flow restrictions to free up more power and to produce the most aggressive sound possible.

SLP Modular Design. SLP manufactures their Mustang catback exhaust systems with a unique modular design that allows you to easily and quickly swap out the included mufflers with any of the other SLP mufflers or resonators they make to suit your driving needs.

High Quality Construction.   The Loudmouth "shotgun" resonators are constructed from hand-polished 304 stainless steel and are embossed with the classic SLP logo. They have a high flow design and measure in at 2.5" ID/OD, 4.5" Body Diameter, and a 18-3/16" Overall Length.

Application. These SLP Loudmouth Resonators are designed to easily replace the existing mufflers or resonators in any of SLP's 1979 to 2004 Mustang Cat-Back exhaust systems. The may also be used in the fabrication of custom exhaust systems.

Fitment: 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 Details

What's in the Box
Hardware included:
  • None - reuses stock hardware
Installation Info
Tech Specs
  • 2.5" ID/OD
  • 4.5" Body Diameter
  • 18-3/16" Overall Length
Will it fit my Mustang?
  • Bullitt - 01
  • Foxbody - 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93
  • Mach 1 - 03, 04
  • V6 - 94, 95, 96, 97, 98, 99, 00, 01, 02, 03, 04
  • Cobra - 94, 95, 96, 97, 98, 99, 01, 03, 04
  • GT - 94, 95, 96, 97, 98, 99, 00, 01, 02, 03, 04

People Who Bought This Item Also Bought

Most Helpful Reviews

replaced my flowmasters

i had flowmasters on my car before i put these in. after the install, i get nothing but compliments from people around me. i have it set up with the bbk shortys and pypes O/R x pype. definately turns heads ...

Read More
Helpful (26)


i bought the slp LM1's. I had flowmaster 40's on my mustang bullitt and they only made noise at about 1950-2200 RPM, these are loud from idle to 6 grand! i lovve them and would recommend them to anybody ...

Read More
Helpful (17)

Overall Rating 4.9 out of 5 stars
Read All 100+ Reviews

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53 Questions / 9 Answers

Ask a Question

Bone stock exhaust I have a bone stock exhaust. I do not have the money to buy a whole catback exhaust and have it installed. So I was wondering if getting these will make enough difference in sound on a stock catback or is it a pointless buy?


  • It would not by any means be pointless, replacement of your stock mufflers is always a plus for performance. However if you do not have the equipment, you would still need to take these to a muffler shop to have them cut away the stock mufflers and replace them with these but if you check around you should be able to get these installed for no more than $100 bucks, and it will sound just as good as buying the setup that bolts from the mid-pipe back. I have the SLP setup and I love it, FYI. I will not go back to flow master after experiencing the sound these babies put out.


Show 3 more answers Helpful (9)

I have a 02 Mustang GT with forged internals, trickflow stage 2 cams, 24lbs injectors, ford performance i take manifold, 78mm BBK throttle, BBK cold air intake, long tube headers, true dual with flowmaster 40s series, aluminum pullies, aluminum driveshaft... i was thinking installing a x pipe with the slp... the slp will make my mustang sound louder and agressive? And the cams are still going to sound nasty?


  • The SLP Loudmouth Center/Center Shotgun Style Resonators will make your car sound louder and the cams will still sound nasty yes!


Helpful (1)

Hi I have a 89 notch would the slp fit with my bbk longtube with catted x pipe ?


  • The SLP Loudmouth Center/Center Shotgun Style Resonators will fit on your 89 Mustang.


Helpful (1)

If I add these to the true dual off-road exhaust system on a 2003 v6, will it be louder or quieter? I was told quieter by a different specialist on your site and wanted to fact check.


  • The SLP Loudmouth Center/Center Shotgun Style Resonators will make your car quieter then what it is now.


Helpful (0)

I have a stock 04 Mach 1 with these simply bolt on with clamps to the stock pipes?


  • The SLP Loudmouth Center/Center Shotgun Style Resonators would not be a direct bolt on replacement for stock mufflers, as the stock mufflers will have the inlet and outlet offset on different sides of the muffler case. Modification to the existing exhaust would be required to install these mufflers.

    Rob D

Helpful (0)

I have flowmaster 40 or 44's with 3 inch tailpipes, will I gain any power by cutting the flows out and replacing them with these on my 93 5.0 Coupe


  • Installing the SLP Loudmouth Center/Center Shotgun Style Resonators in place of your Flowmasters will help build some power, but the differences would be minimal, and restricted to higher rpm gains.

    Rob D

Helpful (0)

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Customer Reviews (100+) Write a Review

Overall Rating 4.9

out of 5 stars

Installation Time:Full Day

Installation Cost:0-$100

  • Loudness / Volume 4.776 4.8
  • Exhaust Note 4.784 4.8
  • Fit & Finish 4.864 4.9
  • Bang For Your Buck 4.76 4.8

  • 5/5

    October 18, 2010

    replaced my flowmasters

    i had flowmasters on my car before i put these in. after the install, i get nothing but compliments from people around me. i have it set up with the bbk shortys and pypes O/R x pype. definately turns heads before they even see me coming! LOVE this product!! has the perfect sound for american muscle cars


    Helpful (26)

  • 5/5

    December 15, 2010


    i bought the slp LM1's. I had flowmaster 40's on my mustang bullitt and they only made noise at about 1950-2200 RPM, these are loud from idle to 6 grand! i lovve them and would recommend them to anybody who owns a v8 mustang. of course though, keep your foot off the gas going by cops!


    Year: 1995

    Helpful (17)

  • 5/5

    July 26, 2009

    Head Turner!

    I use to use nothing but Flowmasters on my Mustangs. I made the change to these baby's on my Mach 1 and it came to life! it will turn heads where ever you go!


    Helpful (15)

  • 5/5

    September 20, 2010

    lm1s are amazing

    amazing sound, cheap price.. Best buy..


    Helpful (12)

  • 5/5

    May 08, 2010

    slp 01 gt

    Just the sound I was looking for and for a good price


    Year: 2001 Submodel: GT

    Helpful (12)

  • 5/5

    April 19, 2010

    love them

    sounds very nice on my 'em.... Thanks Am! you guys rock!


    Helpful (12)

  • 5/5

    August 08, 2010


    This changed my car from a normal road car to an all out drag car! It's much louder than just a normal cat-back and when you get n the high revs it really sounds great! With in an hour of putting these on I got a tone of looks and one guy even pulled up next to me and said "dosnt sound like a cheap one!" and gave me a thumbs up! These are a must for an mustang owner!!!


    Helpful (11)

  • 5/5

    December 09, 2008

    Sound that turns heads

    I have a budget, so I decided to buy these and install them for under $300. When I did - Heaven shed a tear. Its loud, powerful sound irrupted and now my 03 GT stands out. I love being at the Gas station, firing it up, and just smiling as innocent bystanders watch me drive away.


    Year: 2003 Submodel: GT

    Helpful (11)

  • 4/5

    June 20, 2010

    SLP loudmouth 03 Mach 1

    Just got these and had them installed on my 03 Mach 1. Had them welded on at a local Midas shop. Besides the SLP, everything on the exhaust was stock. Sounds great and aggressive. Very pleased.


    Year: 2003

    Helpful (10)

  • 5/5

    May 08, 2010

    amazing buy

    Amazing product for an amazing price. I am using them with lt headers and o/r h pipe, and the result is incredible. great tone at low speeds, and great clarity at wot. i would suggest these to anyone. a breeze to install


    Helpful (10)

  • 5/5

    August 19, 2010


    These are the best mufflers you can put on your car for sound and power!!! however I must warn manuel drivers you will get much worse gas milage not because they affect the car but beccause you will crave the sound when you hit 6grand!!! Best! Best BEST EXHAUST mod you can do!!!


    Helpful (9)

  • 5/5

    May 06, 2011

    Sounds awesome!

    I have these pairs of slp loudmouth resonator mufflers with an o/r h pipe and it sounds just perfect. It has an aggressive tone with a rich deep throaty sound and just a bit raspy. This is the sound I always wanted and I got it with the slp loudmouth mufflers. Was very happy with the price and installation was fairly easy.


    Year: 1991 Submodel: GT

    Helpful (8)

  • 5/5

    April 21, 2010

    If jesus made a muffler

    Its a little tricky to install, but omg when you do; you wont regret it. My mustang has a rich sound, not like a ugly straight headers. I like how you can really hear the cam when it idles. Five Stars.


    Helpful (7)

  • 5/5

    November 19, 2009

    1998 GT

    This is truly something amazing!!! Had them installed with a MAC o/r H-pipe no cats and WOW!! you won't be disappointed I promise. Besides the resonators and the h-pipe the car is completely stock. Basically straight piping though

    Jonathan Romero

    Year: 1998 Submodel: GT

    Helpful (6)

  • 5/5

    Installation Time: Shop Install

    Installation Cost: 0-$100

    April 10, 2013

    amazing sound

    I had the flow master 40s with a stock H, it was too quiet for my taste so i switch the flows for the lm1 that a muffler shop welded on for 60 bucks, as soon as I started the car you can hear a difference much more throtty the way a mustang is or any muscle car is suppose to sound, lm1 are definitely for the people who like the loud muscle car sound if you think its too loud then your driving the wrong cat better drice a hybrid


    Year: 2003 Submodel: GT Edinburg, TX, USA

    Helpful (4)

  • 5/5

    Installation Time: Less than 1 Hour

    September 21, 2011

    Amazing Sound and Performance, Excellent Price!

    Ordered them on a Wednesday night, and got them by Saturday morning. Crazy loud and unbelievable exhaust note. Works extremely well with an O/R X-Pipe.


    Year: 2002 Submodel: GT San Angelo, Texas

    Helpful (4)

  • 5/5

    March 21, 2011

    SLP 1 Resonators

    I just had these resonators installed to replace the stock mufflers. I still have the stock manifolds and stock h-pipe with the 6 cats. After doing a ton of research and living in a emissions sensitive state (MD) I was really excited to put these SLP's on my 1996 GT. After having them installed by an exhaust shop, I couldn't wait to turn the key! And then..... Where's the sound? They were only slightly and I mean slightly louder than stock. It looks like the 6 cats are working overtime to keep the exhaust note down. Rats!


    Year: 1996 Submodel: GT

    Helpful (4)

  • 5/5

    January 26, 2011

    Stay with flowmasters!

    I blew $200 damn dollars swapping these mufflers out! Slp's with an off road x pipe is too damn loud for street use! Reinstalled my Flo's the same day! If u have flo's keep them on! Thanks

    SLP hater

    Helpful (4)

  • 4/5

    July 16, 2010

    Sounds wicked good

    Ordered these and custom fit them to my 2004 Mustang GT. All other exhaust is stock. Sounds excellent deep throaty sound. NOTE: these resonators are shipped in 2.5" diameter. Stock Mustang exhaust is 2.25" diameter. You will need to purchase increasers.


    Year: 2004 Submodel: GT

    Helpful (4)

  • 5/5

    June 25, 2008

    02 GT

    I have these mufflers paired with an o/r x pipe. this is the single loudest setup I have ever heard on a Mustang. It has a very mean sound.

    alan boyle

    Year: 2002 Submodel: GT

    Helpful (4)

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