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  1. #1

    Default Keep the OEM tail pipe or run something else after Flowmaster Muffler

    I was wondering if I should keep the oem tail pipe on after putting the flowmaster 40 in. It's the 3" IN/OUT model and my piping as many of you would already know is 2.75". I'm buying a counter reducer to get it from the cat-back piping to the muffler itself. But should I go from 3" back down to 2.75 and keep the OEM tail pipe? Will it hurt Mpg's/performance? Anythings better than I'm getting now with a straight pipe but I was wondering if there's a common mod that people do when they're in this type of situation. Only reason I'd like to keep the OEM is because its less work and i already have the hangers there.

  2. #2


    Had a buddy do the same thing. Runs stock pipes before and after. Being that minimal size difference I doubt there will be any power loss or power possibily gained by keeping it stock.

  3. #3


    alright thanks and I did. Did everything I was supposed to, took the negative terminal off to get the computer used to the change asap. I just gotta finish the job with some welding it was a sketchy fit and i hear a small leak. But no big issue.

  4. #4


    Posted by drivingore - flowmaster 80

    As per the included instructions, this kit re-uses the stock clamps which needed to be removed from a tack weld strip to keep it in place. This was easily removed with some back and forth bending. Then I got my Kliens to break off the remaining tab on the clamp much closer to the weld and dressed the sharp edge with a file. Fitment and alignment was a snap. The OD of the tips are 4” which is a bit larger than stock. For some reason I did not measure and already packed my OE units away but I think they are like 3 ¼” or 3 ½”. The stock hangers have “tits” on the end of the rods to help them from sliding off the rubber grommet. The Flowmasters do not and two star washers are provided for this purpose.
    I have always used a flowmaster exhaust on my trucks, they have served me well.

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