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Pypes 2.5 in. Stainless Steel Replacement Flow Tube Kit (79-04 All, Excluding 03-04 Cobra)

Market Price $68.99 You Save 13% ($9.00)
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  • Item 20109
  • MPN# PFF10K

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    Features, Video & Details

    • Required for Aftermarket Muffler Installs
    • Mandrel-Bent Construction
    • 2.5" 409 Stainless Steel Tubing
    • Fits 1979 to 2004 Mustangs

    Review & Installation Video

    Review & Install Video

    The Pypes 2.5-inch stainless steel replacement flow tube kit fits '79 to '04 V8 and V6 Mustangs, and '94 to '99 Cobras. You're gonna wanna check out a kit like this if you're upgrading your exhaust in stages by buying a mid-pipe and then buying a set of mufflers, in whatever order, instead of picking up a cat-back. A cat-back comes with these flow tubes, which are located between the mid-pipe and the mufflers, but if you pick up just a set of mufflers instead of a cat-back, you're looking at needing to reuse your stock flow tubes or picking up these Pypes flow tubes if you wanted to create a full aftermarket system from the mid-pipe back. The install for these isn't difficult. It's a one-out-of-three wrenches on the difficulty meter, and you can plan on spending an hour or two on the install. Sitting between the mid-pipe and the mufflers are the flow tubes. Unless you pick up a cat-back, you aren't getting a new set of these. They don't come with new aftermarket mufflers or mid-pipes, and a lot of people want to be consistent with their exhaust. That means not reusing the stock flow tubes. These flow tubes are 2.5-inch, mandrel-bent, 409 stainless steel. And I'll always say this when it comes to exhaust, but stainless steel's going to be your best bet if you want materials that are gonna hold up and not corrode. Compared to aluminized tubing, any stainless steel's gonna be stronger with a longer life. If you compare 409 to 304 grade stainless, 304's gonna be the top-of-the-line material. 409 stainless is still stainless steel, and it isn't a bad material by any means. You still get the longer life and the protection, but 409 usually costs a little bit less than 304. Speaking of cost, you can expect to pay right about $60 for these. These are currently the only flow tubes that you can pick up on the site, so there isn't really anything that we compare them to, but you know that they're 2.5-inch, and they're stainless steel, and they will fit with any setup. When it comes to the install, this is gonna be a one-out-of-three wrenches on the difficulty meter. You can plan on spending an hour or two, tops, on the install. You'll need a socket set and a way to get the car in the air. Depending on what else you're installing with these, the install might change slightly. If you're just installing the flow tubes and nothing else, the install will be straightforward. Your mufflers should have four clamps on them. You'll remove the two front clamps after unbolting the front flow tubes from the mid-pipe. Remove the flow tubes and swap in your new ones. Clamp them to the muffler, and then to the mid-pipe. I would leave things loose until you have them all lined up, and then tighten them down. And that's gonna wrap things up for the Pypes stainless steel replacement flow tube kit for '79 to '04 V8s and V6s, and '94 to '99 Cobras. You can check them out more online, right here at

    Replacement Flow Tubes. Replacing the restrictive stock mufflers is a great idea, but you may end up damaging the factory flow tubes in the process. That is why we offer Pypes 2.5" Stainless Steel Replacement Flow Tube Kit. This kit will replace the piping between the Mid Pipe and the mufflers for a perfect installation.

    Durable Stainless Steel Construction. Pypes uses sturdy 16 gauge 409 stainless steel mandrel bent 2.5" tubing with a ball and socket-style connector for improved flow and includes a set of two 2.5" 304 stainless steel flanges.

    Application. This Pypes 2.5" Replacement Flow Tube Kit is designed for use on the 1979 to 2004 Mustangs when replacing the stock mufflers with aftermarket mufflers or resonators.

    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
    • (2) Flow Tubes
    • (2) Brackets
    Installation Info
    Tech Specs
    Will it fit my Mustang?
    • Bullitt - 01
    • Cobra - 93, 94, 95, 96, 97, 98, 99, 00, 01
    • Cobra R - 93, 95, 00
    • GT - 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 00, 01, 02, 03, 04
    • LX - 87, 88, 89, 90, 91, 92, 93
    • Mach 1 - 03, 04
    • Other - 79, 80, 81, 82, 83, 84, 85, 86
    • V6 - 94, 95, 96, 97, 98, 99, 00, 01, 02, 03, 04

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    8 Questions / 6 Answers

    Ask a Question

    Do I have to buy these if I'm buying an x pipe and flowmaster mufflers


    • Hey Vincent, You do not HAVE to buy them, they just clean up the piping of the exhaust system by replacing your stock pieces. but your x pipe and flowmasters should bolt on regardless


    Helpful (0)

    Do these bolt on directly to the bracket after the cats?


    • The Pypes 2.5 in. Stainless Steel Replacement Flow Tube Kit will connect to the mid pipe's flanges, and then to the mufflers on the opposite end.

      Rob D

    Helpful (0)

    Will the m- 80 pypes mufflers slip into each end of the flow tube? That way I could just clamp them or will they not fit into each other and require welding?


    • This replacement flow tube kit will require welding.


    Helpful (0)

    Where can I find the bolts that go along with this piece?


    • Hello! For this Pypes 2.5 in. Stainless Steel Replacement Flow Tube Kit you could simply just measure and buy the correct length and size hardware you will need.

      Ryan H

    Helpful (0)

    can you use these to replace where the catalytic covers were welded on? or can i use any kind of straight pipe for that?


    • These Flow Tubes are designed for when you replace stock mufflers with aftermarket mufflers or resonators. You may be able to use these to replace the catalytic converters, but it will not be a direct bolt on because of how the tubing is bent.


    Helpful (0)

    x pipe h pipe do these replacement pipes fit for both x pipes and h pipes or r they specific to a set up?


    • They will fit any of the above. These are from the rear flange to the muffler.


    Helpful (0)

    People Who Bought This Item Also Bought

    Customer Reviews (60) Write a Review

    Overall Rating 4.7

    out of 5 stars

    • 5/5

      May 18, 2018

      Great fit

      Great fit and placed the muffers perfect with on3 y pipe


      Year: 1990 Submodel: LX

      Helpful (0)

    • 5/5

      April 27, 2018

      Flow tube kit

      Great packaging. Fast shipping. Perfect condition easy to install.


      Year: 2000 Submodel: V6

      Helpful (0)

    • 5/5

      March 30, 2018

      Flow tube

      Great part ! A must have if your doing the exhaust yourself.


      Year: 1993 Submodel: GT

      Helpful (1)

    • 5/5

      February 03, 2018

      Endless options

      These flow tubes paired with my bbk o/r H pipes now give me the the option and ease of changing out the mufflers and fine tuning the sound of my ride.


      Year: 1995 Submodel: GT

      Helpful (2)

    • 5/5

      January 04, 2018

      Flow pipes

      Fit great and bolt right up to my off road h pipe. Great product.


      Year: 1994 Submodel: GT

      Helpful (2)

    • 5/5

      December 08, 2017

      Flow tube kit SS

      Excellent fit bolted right up to Walker quiet SS mufflers, look good under car


      Year: 1994 Submodel: GT

      Helpful (2)

    • 3/5

      November 15, 2017

      Too low

      These tubes had too much bend for driver side. Which made my Hooker Aero Chamber muffler hang low. My 5.0 has an auto trans and Bassani stainless off-road X pipe. I used different ones for my app.


      Year: 1993 Submodel: LX

      Helpful (2)

    • 5/5

      September 11, 2017

      Flow tube review

      Excellent fit. Truly a bolt on install. Solid construction.


      Year: 2001 Submodel: GT

      Helpful (2)

    • 5/5

      September 09, 2017


      They worked perfectly it helped make it sound great


      Year: 1995 Submodel: GT

      Helpful (2)

    • 5/5

      August 28, 2017

      Flow tubes

      Perfect fit bolt right up. Made much easier. And if ever need to remove its simple cant ask for more then that


      Year: 2002 Submodel: GT

      Helpful (2)

    • 5/5

      August 22, 2017

      Replacement flow tube kit

      They fit perfectly on my 1987 LX mustang. Bolted on to the H pipe and had them welded to the mufflers


      Year: 1987 Submodel: LX

      Helpful (1)

    • 4/5

      August 08, 2017

      Needed as an extension

      I needed to extend my piping from my mufflers to reach my shorty mid pipe. This made the job a lot easier. Took it to the shop and they welded it on.


      Year: 2004 Submodel: V6

      Helpful (1)

    • 5/5

      June 29, 2017

      Made work easy

      Used these with a muffler swap and made the job go so much easier. I would recommend these to anyone swapping exhaust out.


      Year: 1992 Submodel: GT

      Helpful (1)

    • 5/5

      June 21, 2017

      Flow tubes

      Fit was perfect would buy again I purchase the flow tubes for my Flowmasters they work perfectly thanks again American Muscle.


      Year: 1989 Submodel: GT

      Helpful (3)

    • 5/5

      June 11, 2017

      A must have when installing 2 1/2 inch mufflers

      Not much to say, they are 2 1/2 inch flow tubes, and seem to be of excellent quality.


      Year: 1999 Submodel: GT

      Helpful (1)

    • 3/5

      April 26, 2017


      Not well bent . No matter how i turn them the fit was poor. Muffler hang kinda low because if it. Not happy.


      Year: 1988 Submodel: LX

      Helpful (1)

    • 5/5

      April 17, 2017

      Great fit

      They fit great with the BBK X pipe to Pypes pipe mufflers we had on the car already


      Year: 1989 Submodel: GT

      Helpful (1)

    • 5/5

      March 22, 2017

      Perfect Fit

      A Must have for switcing midpipes and aftermarket mufflers. Good fit, easy install.


      Year: 2001 Submodel: GT

      Helpful (2)

    • 3/5

      March 20, 2017

      might work better in a different application.

      I had installed an american thunder cat back exhaust from flowmaster on my 89 lx convertible. but I preferred the sound of my magnaflow system on my 94 convertible. but I liked the tailpipes from the american thunder system better so I bought some magnaflow mufflers and these pipes to replace the american thunder mufflers. unfortunately they are about 2 inches too short to work well, the tail pipe kept hitting the axle control arms and I could not get them connected adequately. I ended up using some short 2 1/2 inch id to 2 1/2 inch od adapters to make up the difference and then everything was great. the quality of the tubes is excellent the fit was fine, no leaks. no issues. if they were 2 inches longer they would have been perfect.


      Year: 1989 Submodel: LX

      Helpful (3)

    • 5/5

      February 26, 2017

      Great fit

      Ordered these for my upgrade to 2.5 inch exhaust and it was direct bolt on no welding used old hardware.


      Year: 1986 Submodel: Other

      Helpful (3)

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