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SLP Loudmouth Resonators - 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

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Most Helpful Reviews

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.

Helpful (3)

Wake up your V6

I put these on my lightly modded 99 V6 and let me just say I still get excited when I start up my car. Only mods I've added are a SR cold air intake and MAC dual exhaust. And for those who are wondering ...

Read More
Helpful (1)

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

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45 Questions / 7 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 (6)

I have BBK long tube headers, off-road h pipe, and the SLP Loudmouth II cat back system, which is LOUD and sounds amazing. Are the Loudmouth "shotgun" resonators louder?


  • Hello! The SLP Loudmouth Resonators are louder than the "bullet" style resonators on your catback.


Helpful (0)

I have flowmaster cat back on my 03 mach 1, if I change out the mufflers would it have the same tone as the slp catback


I have a 2002 mustang v6. I already have a flowmaster on the car (I don't know which one because I just bought it and the guy I bought it from didn't know either). I wanted to know which would sound most aggressive and loud, between the super 10 series flowmaster muffler or the slp loudmouth resonators? I have everything else stock on the car by the way


  • Hello david, SLP loud mouth is the most aggressive system that we carry, though of course it will sound differently in v6 than it does a v8


Helpful (0)

My current mufflers are 3 inches in diameter, will these fit as a replacement even though there 2.5 inches?


  • These will be able to fit for a replacement, just make sure that you have a trust exhaust shop step down to 2.5" when having these installed.


Helpful (0)

I have an 04 V6 with the pypes street-pro dual exhaust system. I'm looking to replace those mufflers with a set of these. Would this be possible?


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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 4.790476 4.8
  • Exhaust Note 4.8 4.8
  • Fit & Finish 4.838095 4.8
  • Bang For Your Buck 4.761905 4.8

  • 5/5

    Installation Time: Less than 1 Hour

    October 18, 2016

    Wake up your V6

    I put these on my lightly modded 99 V6 and let me just say I still get excited when I start up my car. Only mods I've added are a SR cold air intake and MAC dual exhaust. And for those who are wondering if it'll make your car sound "ricey" TRUST ME it's nothing remotely close to it. People consistently mistaken my V6 for a gt. I'd recommend this product to anyone.


    Year: 1999 Submodel: V6

    Helpful (1)

  • 5/5

    Installation Time: Afternoon

    September 23, 2016

    04 Duals

    Installed highflow cats and cut the Ypipe into true duals with no X or H pipe with SLP Resonators and out the back. I love them and they sound great. They do increase the volume considerably and are mean and angry.....hehe. If you are wanting to wake the beast then I highly recommend these.


    Year: 2004 Submodel: V6

    Helpful (1)

  • 5/5

    July 27, 2016

    Absolutely worth It

    Totally worth the money, sounds beautiful, turns heads everywhere and get a lot of compliments


    Year: 1999 Submodel: GT

    Helpful (1)

  • 5/5

    Installation Time: Shop Install

    July 03, 2016

    Extremely Loud

    I installed SLP lm1 with reonator cats deleted "straight pipes" and it was extremely loud. In1200RPM loud My Stang was stock only SR cold air intake and it's sounds like stroker.


    Year: 2002 Submodel: GT

    Helpful (1)

  • 4/5

    Installation Time: Less than 1 Hour

    May 31, 2016

    Great Sound

    Just what I wanted. I had some flowmasters but wasn't really happy with the sound. The SLP resonators sound bad to the bone. Keep in mind they are designed to fit into the SLP cat back system.


    Year: 1993 Submodel: Other

    Helpful (1)

  • 5/5

    Installation Time: Shop Install

    Installation Cost: 0-$100

    February 08, 2016

    Sound Amazing

    I was looking for a replacement for my flowmasters 40 series because they were too quiet. I was hesitant to buy these because of the price, but I am very happy that I did! It sounds so much better than it did and is now much more enjoyable to drive! It is now a real head-turner and sounds much more aggressive without being too loud.


    Year: 2003 Submodel: GT Washington Mo

    Helpful (1)

  • 5/5

    Installation Time: Afternoon

    April 20, 2014

    Slp is the best

    I love the sound these gave my fox I had flowmasters before but they just weren't enough.


    Year: 1993 Submodel: GT Germany

    Helpful (1)

  • 5/5

    Installation Time: Shop Install

    Installation Cost: 0-$100

    June 22, 2012

    Fate led me to these.

    So I had ordered the M80 mufflers because of the price point, yet once I placed the order I found out they were on backorder. Taking this as a sign of fate, I cancelled that order and placed a new one for these SLP's. BEST DECISION I'VE MADE HANDS DOWN. I was worried about them being overly loud, but their tone and volume are perfect. I had a shop install them for $60 and it took 20 minutes tops. I just had these welded into my 100% otherwise stock exhaust system and am so thrilled with how it makes my '01 cobra sound. BUY THEM!


    Year: 2001 Submodel: Cobra

    Helpful (1)

  • 5/5

    Installation Time: Less than 1 Hour

    March 03, 2012

    Amazing Sound & Finish!

    For those whom are skeptical on purchasing these SLP's, no need to worry! The sound is amazing over previous Magnaflows. Setup on stock (4) catted, BBK X-pipe, SLP Resonators, not overly loud; and with an perfect down rev sound. For those of you thinking twice, look no further. Once they were installed, I simply could not keep a smile off my face as I drove for miles on end. I cannot wait to see how much better it would sound with an O/R setup. Just as always, American Muscle has been outstanding with their service, and received within one week time on the west coast. AM, look forward to seeing me again soon!


    Year: 2001 Submodel: GT Southern California

    Helpful (1)

  • 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 (3)

  • 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

    December 30, 2009


    it doesn't get any nastier sounding than this..i'm not pushing my hp yet, but if i heard me coming down the road, i wouldn't wanna race me haha..amazing sound when added with offroad x-pipe


    Helpful (2)

  • 4/5

    December 22, 2009

    2000 GT

    I put these on my 2000 gt. i have ford racing shortie headers, magnaflow o/r x-pipe, with loudmouths. i was expecting it to be too loud but they sound really good. the only time it is too loud is when you put the pedal to the floor. i have very pleased with the louthmouths! good buy! thanks AM


    Year: 2000 Submodel: GT

    Helpful (1)

  • 5/5

    November 19, 2009

    Slp resonators

    I had the flowmaster cat back system in b4 on my 02 GT but wanted something louder so I bought these and they are perfect! they sound Loud and mean! AM is the best when it comes to mustangs!


    Year: 2002 Submodel: GT

    Helpful (2)

  • 5/5

    September 27, 2009

    97 GT

    Was tired of having that stock sound out of my V8 and really didn't know what mufflers to go wit, everyone has flows so I wanted to try the slp's and man!!! It is by far the best descion I have made for my stang!!! The sound is so crazy!!! I wake up my neigbors n scare everyone when im flying by the highway!!! Awesome product!!! Thanx AM!!!

    Felix Flores

    Year: 1997 Submodel: GT

    Helpful (1)

  • 5/5

    August 11, 2009


    I purchased the SLP LM2 Catback last summer I ordered the SLP LM1 Resonators last week and put them on today... THESE ARE AWESOME! The LM2 are slightly deeper with a more low growl The LM1 are slightly louder, with a very slight rasp and a WAY more open feel So if you are thinking about these and are worried they will be too loud or too raspy...THEY ARE NOT...Go with these (SLP LM1) and you wont be disappointed...I cant wait to hear what my Magnaflow Catted X will sound like when I put it on at the end of the month!!! SLP ALL THE WAY!


    Helpful (1)

  • 5/5

    February 17, 2009


    I had Flowmaster 40s with a dump on my 97 GT, and it sounded nice and all dont get me wrong, but I wanted something louder. Found it! I looked into Borla Stingers and Magnapacks, they were way too expensive. These Loudmouths sound just as good for a fraction of the price. They are the best!


    Year: 1997 Submodel: GT

    Helpful (1)

  • 5/5

    February 02, 2009


    swapped out my flowmasters for these, couldnt have been a better decision.


    Helpful (2)

  • 5/5

    January 15, 2009

    Great price

    These resonators make your Mustang sound sick. They are extra loud, and for the price you cant get much better.


    Helpful (1)

  • 5/5

    May 15, 2008


    I love Flowmaster, but I found my new favorite mufflers!

    TONY 2002 GT

    Helpful (1)

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