GM Truck Club
Founded in 2004 ~ We're the #1 Chevy Truck & SUV Forum.
Silverado & Sierra | Tahoe & Yukon | Suburban & Yukon XL | SUV & CROSSOVER
Results 1 to 3 of 3
  1. #1
    Sr. Apprentice
    Join Date
    Mar 2014
    Pikeville kentucky

    Default Flowmaster exhaust

    Alright guys, I'm wanting to get a set of flowmasters put on my truck but confused on what size to get,

    what at would be the best to get 2inch in out out?
    also can I get 2 mufflers put on? Would it sound better with 2?

  2. #2
    Jr. Apprentice
    Join Date
    Jan 2014
    N Kentucky/Cincinnati


    Just saw this thread. How did you make out?

    I had a flowmaster on my '04 with dual outs (one on each side). Getting the one pipe out the driver's side was a PITA. Took the guy over an hour to get it right (snaked it in front of the spare tire).

    I had a Flowmaster 40 (I think). I'll tell you what NOT to do. Don't go with the Delta 40 and don't upsize the pipes. Resonance at about 70 mph was horrendous - like your teeth were going to rattle out of your jaw. I replaced the Delta 40 with the regular 40 and it was tolerable. Significant low-end torque loss from upsizing the pipes - that was a big mistake. Sounded great at idle, though.

    I'm told the 50 is much better for that engine.

    When that one needed replacing, I went with a Magnaflow. Nowhere near as aggressive sounding and only one outlet pipe, but since I'm back living in the suburbs, it made sense.
    2004 Avalanche Z71 Silver Birch Metallic - Purchased new 04/2004 - Traded 07/2013 with 122,998 miles.
    2007 Avalanche LTZ Sunburst Orange Metallic - Purchased 07/2013 with only 16,686 miles!

  3. #3


    I put a Flowmaster 40 on a 350-V8 with the 2" through... it's on a 1955 Chevy. My dad loved it but I could barely hear the radio over the exhaust note. I actually swapped the exhaust on mine to a Magnaflow as well, for similar reasons as above. I left the 2" in and the 1.5" out as stock for my truck. Specifically I did that because I was worried about not having enough back-pressure after some issues cropped up with a friend's 2" through on his GMT-800 Silverado. The muffler guy mentioned I would barely hear a difference between the two but was of the opinion that it's engineered a specific way, why would you change it without a reason and understanding of all it affects. Just my thoughts on the matter...
    2007 Silverado 1500 NNBS - Work truck and daily driver
    2002 Malibu - The wife's car, for now. I smell a Suburban in my future
    1976 Stingray - NOW OVER 100,000 MILES!

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts