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The Walker® Quiet-Flow® SS 21577 exhaust muffler is engineered with 100% stainless-steel construction, offering superior corrosion resistance and durability compared to aluminized alternatives. This direct-fit replacement provides OE-style pipe routing, hangers, and brackets for simple installation, while its louvered tube design and domed heads reduce radiated noise for premium, factory-style sound.
Designed to last, this muffler features spun-locked heads and mechanically joined tubes to withstand thermal expansion and contraction, ensuring long service life for GM full-size truck and SUV applications.
100% Stainless-Steel Construction for maximum corrosion resistance
OE-Style Fitment: Direct-fit bolt-on design, no welding required
Premium Acoustic Control: Louvered tubes reduce noise levels
Durable Build: Spun-locked heads resist deformation
Validated Performance: Flow-tested and sound-tested
Backed by Walker’s Limited Lifetime Warranty
| Specification | Detail |
|---|---|
| Shape | Oval |
| Finish | Aluminized |
| Inlet Type | Pipe Connection |
| Outlet Type | Pipe Connection |
| Inlet Inside Diameter | 3.000 in |
| Body Height | 7.000 in |
| Body Length | 24.000 in |
| Body Width | 9.000 in |
| Overall Length | 29.000 in |
| Inlet Location | Offset |
| Outlet Location | Offset |
| Inlet Quantity | 1 |
| Outlet Quantity | 1 |
| Body Material | Stainless Steel |
| Hanger Included | No |
| Reversible | No |
| Universal or Specific Fit | Specific |
| Grade Type | Premium |
| Inlet Offset | 1.625 in |
| Outlet Outside Diameter | 2.750 in |
Avalanche (2007)
6.0L V8 (364 cid)
Silverado 1500 (2007–2013)
4.3L V6 (262 cid)
4.8L V8 (294 cid)
5.3L V8 (325 cid)
6.0L V8 (364 cid, 2007–2008)
Suburban 1500 (2007)
6.0L V8 (364 cid)
Sierra 1500 (2007–2013)
4.3L V6 (262 cid)
4.8L V8 (294 cid)
5.3L V8 (325 cid)
6.0L V8 (364 cid, 2007–2008)
Yukon XL 1500 (2007)
6.0L V8 (364 cid)
Direct-fit, bolt-on design – no cutting or welding required
Verify inlet size (3”) for compatibility with factory piping
Not reversible – must be installed in correct orientation
Reuse or replace existing clamps/hardware depending on condition
No hanger included – ensure OE hanger is intact and reusable
Professional installation recommended for proper alignment and sealing
Designed for stock exhaust systems; modifications may affect fitment
Order Processing
All orders are processed and shipped within 24 hours of purchase (excluding weekends and holidays).
Orders placed after 3:00 PM EST may ship the following business day.
Shipping Methods
Customers select their preferred shipping method and speed at checkout.
Shipping times are determined by the carrier and cannot be guaranteed by us.
Tracking information will be provided once your order has shipped.
Shipping Coverage
If your package arrives damaged, please notify the delivery driver immediately and contact the shipping carrier to file a claim.
You must report any missing or damaged items within 14 days of delivery.
After this time, we cannot be held responsible for lost or damaged items.
Return Window
You have 30 days from the date of delivery to request a return.
After 30 days, we are unable to accept returns, exchanges, or refund requests.
Eligibility
Items must be returned in their original condition—unused, unwashed, and with all tags and packaging intact.
Certain products may not be eligible for return (e.g., special-order items, customized products, or perishable goods).
Items that have been altered, installed, or modified cannot be returned.
Return Process
Contact our Customer Support team to request a Return Authorization (RMA) before sending items back.
Once your return is approved, you’ll receive instructions on where to send the product.
Customers are responsible for return shipping costs unless the item was defective or incorrect.
Refunds
Refunds are issued to the original payment method once the returned item has been received and inspected.
Please allow 5–10 business days for the refund to appear on your account.
In some cases, a restocking fee may apply (if applicable, this will be disclosed during your return authorization).
