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Flowmaster 40 Series Offset Muffler - Stainless Steel 2.5 in. (79-04 All, Excludes 99-04 Cobra)

9 Reviews
Our Price

$87.08

  • Item #18433
  • MPN# 8042543

  • Market Price $96.99
  • You Save 10% ($9.91)
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Product Videos Customer Photos
Features
  • Signature Flowmaster Sound
  • Original two chamber technology
  • Offset inlet and outlet design
  • 2.5" inlet/outlet diameter
  • 409s stainless steel construction
  • Sold individually
Description
That Flowmaster Sound. Improve your Mustangs exhaust flow for an increase in horsepower and a deeper throatier exhaust note with a set of Flowmaster 40 Series Mufflers for a truly classic muscle car sound.

Superior Design. The Flowmaster 40 Series Mufflers are MIG welded from durable 16 gauge 409s stainless steel for durability and value. The 40 series mufflers use Flowmasters original two chamber design to increase power and sound. And each muffler is embossed with the "Flowmaster" name so you know it is the real article.

Application. The 40 Series Muffler's outer case measures 4" x 9.75" x 13", and features a 2.5" diameter inlet and outlet in an offset configuration. This is the perfect muffler for the 1979 to 2004 Mustangs. Excludes 1999-2004 SVT Cobra.

Mustang 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
  • (1) Muffler
Installation Info
Tech Specs
40 Series Delta Flow versus 40 Series Original versus Super Flow 44 Series
  • Minimizes interior resonance
  • Aggressive exterior tone
  • Two Chambered Muffler
  • Made of Aluminized Steel
  • No minimization of interior resonance
  • Aggressive tone inside and out
  • Two Chambered Muffler
  • Made of Aluminized Steel
  • Delta Flow technology minimizes interior resonance
  • Aggressive deep powerful tone
  • Two Chambered Muffler
  • Made of Black Aluminized Steel
Fitment
  • 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
  • GT - 94, 95, 96, 97, 98, 99, 00, 01, 02, 03, 04

Most Helpful Reviews View All

Overall Rating 4.8/5 Write a Review
5/5
FLOWS !

Best option for your stock muffelr replacement, not too loud, nice low rumble, perfect, sounds great under the V6.

Helpful (1) (0)

5/5
Awesome!

Very pleased with my purchase. Way more aggressive sound and note than stock muffler. Flows much better also. Definitely recommend for anyone looking to make their 99-04 v6 more aggressive sounding.

Helpful (1) (0)

Videos

Customer Photos (2) View All

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Q & A (2 Questions, 2 Answers) Ask a Question

Want the stainless steel flowmaster 40's. Are both sides the same? Are the flowmaster 40 mufflers for my 1989 mustang gt the same for both sides or is there a left and right muffler? I need the stainless 2.5". Thanks, Bruce

BA1964 Year: 1989 Model: GT

Good Question (0) (0)
  • Yes! The offset by offset can work on either Side! I hope this answers your question.

    Helpful (0) (0)

    JayM99 Year: 1999 Model: GT

Answer This Question

does this product come with the exhuast tips?

luisc787 Year: 2002 Model: V6

Good Question (0) (0)
  • No it does not

    Helpful (0) (0)

    syed Year: 2000 Model: GT

Answer This Question

Reviews (9) Write a Review

  • 5 Stars .78 78%
  • 4 Stars .22 22%
  • 3 Stars 0 0%
  • 2 Stars 0 0%
  • 1 Stars 0 0%
4.8

out of 5 stars

9 Customers Recommend this Product

Installation Time:Weekend

Installation Cost:$100-$250

  • Loudness / Volume: 4.555555 4.6/5
  • Exhaust Note: 4.666667 4.7/5
  • Fit & Finish: 4.333333 4.3/5
  • Bang For Your Buck: 4.666667 4.7/5
Filter By Sort By
  • 5/5 Yes, I recommend this product

    November 08, 2012

    Awesome

    I've spent countless hours looking up exhausts and mufflers online! When I finally made my decision I choose the flowmaster 40 series mufflers in stainless steel. And let me tell u I couldn't be more happier! The sound is amazing! The stainless steel finish looks good too! I highly recommend this product to anyone who wants there car to come alive! Thanks AM!

    JayM99

    Year: 1999 Model: GT Driving Style: Daily Driver 'Stangs I have owned: 1 Whittier, CA, USA

    Helpful (1) (0)

  • 5/5 Yes, I recommend this product

    September 21, 2012

    Awesome!

    Very pleased with my purchase. Way more aggressive sound and note than stock muffler. Flows much better also. Definitely recommend for anyone looking to make their 99-04 v6 more aggressive sounding.

    Caesarion

    Year: 1999 Model: V6 Driving Style: Daily Driver 'Stangs I have owned: 1 Michigan, USA

    Helpful (1) (0)

  • 5/5 Yes, I recommend this product

    August 06, 2012

    FLOWS !

    Best option for your stock muffelr replacement, not too loud, nice low rumble, perfect, sounds great under the V6.

    iSayWhtSheFeels

    Year: 2000 Model: V6 Driving Style: Daily Driver 'Stangs I have owned: 1 Indianapolis, IN, USA

    Helpful (1) (0)

  • 5/5 Yes, I recommend this product

    April 18, 2014

    Perfect muffler!!

    This muffler is awesome. It makes your v6 sound much deeper and more aggressive. Not like those mufflers that will make your care sound like a ricer, this makes your v6 sound like a v8!

    2004v6mustang

    Year: 2004 Model: V6 'Stangs I have owned: 1 Goodman, MO 64843, USA

    Helpful (0) (1)

  • 5/5 Yes, I recommend this product

    March 13, 2015

    Flowmaster 40 series stainless mufflers

    These mufflers are great! It's amazing how just changing out the stock mufflers can make my 4.6 sound so mean! They look great and have a nice classic, deep muscle car rumble.

    MaxPower

    Year: 2001 Model: GT Driving Style: Show 'Stangs I have owned: 4 Lakeland, FL

    Helpful (0) (0)

  • 4/5 Yes, I recommend this product

    June 27, 2014

    Good Product

    Mustang has louder tone and note to it. Notice improvement!

    Lt535

    Year: 2004 Model: GT 'Stangs I have owned: 2 Big Stone Gap, VA 24219, USA

    Helpful (0) (0)

  • 5/5 Yes, I recommend this product

    May 23, 2014

    killer sounds, defanetly a head turner

    drivin down the road i love that i can turn heads my giving my car the gas, the deep sound just fits the car great and im very happy with it

    mikesil44

    Year: 2002 Model: V6 Driving Style: Daily Driver 'Stangs I have owned: 5 RI

    Helpful (0) (0)

  • 5/5 Yes, I recommend this product

    October 18, 2013

    Awesome

    Installed these on my gt and sound amazing. I had them welded in bc clamps and adapters are a pain. Welding is the way to go !

    Jb02gt

    Year: 2002 Model: GT Driving Style: Daily Driver 'Stangs I have owned: 1 New York ny

    Helpful (0) (0)

  • 4/5 Yes, I recommend this product

    May 17, 2013

    SS 40 Series

    The only complaint I have is the mufflers don't have the hanger welded to it like the magnaflos had on the side closest to the rear axle. Other then the hanger missing its the best sounding muffler out there.

    Top 500 Contributor

    kwmiked04

    Year: 2004 Model: GT Driving Style: Street / Strip 'Stangs I have owned: 1 shelton CT

    Helpful (0) (0)

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