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- The Flowmaster 70 Series Big Block II Muffler is specially-made for big trucks, SUVs, RVs and any other towing vehicle
- Accommodates maximum exhaust volume for handling huge engines at maximum load
- Provides outstanding boosts to power and torque to towing excellence
- Adds a throaty mild exhaust tone to your vehicle without overpowering volume
- Utilizes Flowmaster's exclusive Delta Flow technology for superior scavenging and minimal interior resonance
- Crafted from aluminized steel for corrosion resistance and precision mig welded for maximum durability
- Casing embossed with the Flowmaster name
- Fits vehicles that do not match the 50 Series Big Block Muffler
- Your Flowmaster 70 Series Big Block II Muffler carries a 3-year warranty
Maximum flow volume, maximum efficiency, maximum power. The Flowmaster 70 Series Big Block II Muffler does it all for your big, bad truck, SUV, RV or other towing vehicle. With its massive chamber, the Flowmaster 70 Series handles the output of huge working engines at their highest load, boosting torque right when you need it.
The Flowmaster 70 Series Muffler also uses exclusive Delta Flow technology for the least possible interior resonance, thanks to precision deflectors in the chamber. These exact parts also aide exhaust gas scavenging for scraping together the most power and torque possible.
The 70 Series Big Block II Muffler boasts the quality construction you'd expect from Flowmaster. Each Flowmaster Muffler is built with 16-gauge aluminized steel for corrosion resistance and fully mig-welded for maximum durability. Best yet, your Flowmaster 70 Series Big Block II Muffler boasts a 3-year warranty.
- Flowmaster 70 Series Big Block II Mufflers come in a variety of inlet/outlet configurations and sizes, shown above. Select the inlet/outlet diameter you need from the dropdown menus above.
Flowmaster 70 Series Big Block II Mufflers Customer Reviews
46 Customer Reviews
Reviewed by Ronald C (Denison, TX) Reviewed for a 2017 Chevy Silverado — Oct 31, 2017 4:35 PM
Installed new Flowmaster 70 series muffler on my truck with dual exhaust pipes coming out the rear of truck. Truck sounds great just the tone that I wanted.
Reviewed by patrick m (BALLWIN, MO) Reviewed for a 2015 Ford F-150 — Oct 04, 2017 5:29 AM
THE MUFFLER HAS A SLIGHT RUMBLE, WHICH IS WHAT I WANTED. I PLACED MY ORDER BY PHONE TO MAKE SURE I GOT THE RIGHT ONE. I ORDERED THE ONE WHICH WAS OFFSET. I TOOK IT TO THE LOCAL MUFFLER SHOP TO HAVE IT INSTALLED. THEY SAID IT DIDN'T LINE UP AND HAD TO MAKE A CUSTOM "S" PIPE TO MAKE IT WORK, COST ME AN EXTRA $50.
Reviewed by Chad H (Lake Charles, LA) Reviewed for a 2013 GMC Sierra — Mar 29, 2017 4:55 AM
Overall, I am happy with the muffler. As my daily driver and primary family vehicle used for traveling, I didn't want anything too loud. This muffler is a little louder than what I expected, comparing to a 50 series installed on same truck. I removed the 50 series last year and had to go back with the factory muffler due to a drone when pulling my trailer or boat. Using Flowmaster's sound chart, I thought the 70 series would be only choice as it looked to be the quietest muffler Flowmaster makes
Reviewed by Jeffrey S (Warsaw, MO) Reviewed for a 2008 GMC Sierra — Nov 10, 2016 3:22 AM
I purchased this muffler to replace a smaller flowmaster muffler that was too loud for my application. This has the performance of the flowmaster technology without all the noise.
Reviewed by Glenn S (Waupaca, WI) Reviewed for a 2015 GMC Acadia — Jun 15, 2016 5:15 PM
I was excited about installing this muffler and expected it to be real quiet better than the origional equipment well not so I still needed the resinators. I wish I was told I would need something to keep the drone noise out of the cabin. There are a lot of V/^ engines out there and more testing should be done to eliminate the drone noise and still have better flow.