Flowmaster 70 Series Big Block II Muffler

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Fitment Info

Deep drone muffler Delta Flow technology Improved fuel economy Fully MIG welded Manufacturer's warranty Made in the USA

Our #1 value is customer service.

We believe in doing right by our customers, no matter what it takes.

In keeping with that, we offer a “perfect fit guarantee” that ensures your satisfaction on 3 levels: low price, free shipping, and perfect fitment.

- Alan Marek, Founder of PartCatalog.com

The Lowest Price Anywhere--Guaranteed

At PartCatalog, we’ll beat any competing vendor’s price. And we’re so confident in our rock-bottom prices that we’ll refund the difference if you find a lower price elsewhere.

Free Shipping Both Ways

Our “free shipping both ways” policy means that returns and orders ship free of charge. When you place an order, you pay only the list price and any applicable taxes. We cover the shipping to save you money and ensure timely delivery.

100% Guaranteed to Fit

In the highly unlikely event of a fitment problem, we’ll return your purchase at no cost to you. We pay return shipping on all orders, so it won’t cost you a penny to send back a defective part.


  • Deep drone muffler that converts exhaust noise to a low non-aggressive drone
  • Long case design suitable for heavy-duty vehicles
  • Delta Flow technology for unrestricted exhaust flow
  • Large unrestricted exhaust volumes for better fuel economy
  • Available in two options: stainless steel and aluminized steel
  • Fully MIG welded to stay strong and last long
  • Manufacturer's warranty of excellent quality and performance
  • Made in the USA with authentic materials in an economy-building industry
Deep Drone Muffler

Deep Drone Muffler

The Flowmaster 7 big block muffler produces a deep drone that is not aggressive, suitable for drivers who prefer a quieter drive. It is especially ideal for powerful vehicles with a heavy-duty capacity. It is affordable and guaranteed to add value to your vehicle for years.

Long Case Design

Long Case Design

The long case design helps it process high volumes of exhaust flow for heavy and powerful vehicles. It is suitable for tow vehicles and heavy trucks that need such power with minimal noise levels.

Delta Flow Technology

Delta Flow Technology

The muffler is designed with Flowmaster's exclusive Delta Flow technology that ensures an unrestricted flow of exhaust gases with minimum interior resonance. This makes for increased horsepower, reduced interior noise and optimal performance.

Improved Fuel Economy

Improved Fuel Economy

Large exhaust volumes with unrestricted flow help to save up on fuel. The Flowmaster 70 big block II muffler is made to process such huge volumes for large trucks.

Available in Two Options

Available in Two Options

The muffler is available in two finishes: aluminized steel and stainless steel. Both are high-quality, rust and corrosion resistant and will add value to your vehicle for years.

Fully MIG Welded

Fully MIG Welded

The muffler is fully MIG welded for super strength. It will withstand years of weather and road abuse to retain its strength and toughness for years.

Manufacturer's Warranty

Manufacturer's Warranty

Flowmaster guarantees that your muffler is of excellent quality and will serve you to satisfaction. For every purchase, you are provided with a limited lifetime warranty for the stainless steel and a three-year warranty for the aluminized steel muffler.

Made in the USA

Made in the USA

Flowmaster 70 big block mufflers are proudly made in the USA with local labour and authentic equipment. The company employs thousands of Americans every year to contribute to the growth of the economy.

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Lifetime Limited Warranty applies to Flowmaster stainless steel mufflers (excluding FlowFX series).
Three (3) Year Limited Warranty applies to Flowmaster aluminized steel mufflers.
Part Numbers

The following part numbers are available in this product line:

524703, 52571, 52572, 52573, 53070, 530702, 53071, 53072, 853072

To purchase this product for your vehicle, please select the Year, Make and Model of your vehicle at the top of this page.

Chevrolet (1964-2015)

Avalanche, Avalanche 1500, Blazer, C10, C10 Suburban, C1500, C1500 Suburban, C20, C2500, C30, Chevelle, El Camino, K10, K10 Suburban, K1500, K1500 Suburban, K20, K2500, K30, K5 Blazer, Malibu, Monte Carlo, R10 Suburban, R1500 Suburban, R20 Suburban, Silverado 1500, Silverado 1500 Classic, Suburban, Suburban 1500, Tahoe, V10 Suburban

Dodge (1979-2010)

D100, D150, D200, D250, D300, D350, Dakota, Durango, Ram 1500, Ram 2500, Ram 3500, W100, W150, W250, W350

Ford (1987-2014)

Expedition, Explorer, Explorer Sport Trac, F-150, F-150 Heritage, F-250, F-250 Super Duty, F-350, F-350 Super Duty

GMC (1979-2013)

C1500, C1500 Suburban, C2500, C2500 Suburban, C3500, Jimmy, K1500, K2500, K3500, Sierra 1500, Sierra 1500 Classic, Yukon, Yukon XL 1500

Lincoln (1998-2010)


Nissan (2004-2013)

Armada, Titan

Pontiac (1964-1972)


Toyota (2000-2013)

4Runner, Tundra


Customer Reviews

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Flowmaster Muffler - 70 Series - 53071
Review by Dennis M.
Good price and prompt service.
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