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The WALKER® Quiet-Flow® SS 21400 muffler provides an OE-style sound profile, industry-leading corrosion resistance, and precise fitment for full-size Chevrolet and GMC truck platforms. As the only broad-market muffler line that uses 100% stainless-steel construction, it delivers a significantly longer lifespan than traditional aluminized mufflers, especially in high-moisture or corrosive environments.
This unit features OE-style domed heads, louvered tubes, and mechanically joined internals to maintain proper acoustic tuning and reduce radiated noise. Walker’s direct-fit engineering ensures quick, bolt-on installation without cutting or welding.
100% Stainless-Steel Construction for superior corrosion resistance
OE-Style Fitment with model-specific hangers and pipe routing
Factory-Style Sound using louvered tubes & domed heads
Durable Mechanical Joints withstand thermal expansion
Acoustic & Flow Tested for dependable OE-level performance
Backed by Walker Limited Lifetime Warranty
| Specification | Detail |
|---|---|
| Shape | Oval |
| Finish | Natural |
| Inlet Type | Pipe Connection |
| Outlet Type | Pipe Connection |
| Inlet Inside Diameter | 2.500 in |
| Outlet Inside Diameter | 2.750 in |
| Body Height | 7.000 in |
| Body Length | 25.000 in |
| Body Width | 9.000 in |
| Overall Length | 39.500 in |
| Hanger Included | Yes |
| Inlet Location | Offset |
| Outlet Location | Offset |
| Inlet Quantity | 1 |
| Outlet Quantity | 1 |
| Body Material | Stainless Steel |
| Universal or Specific Fit | Specific |
| Grade Type | Premium |
| Inlet Offset | 1.750 in |
2.7L V6 (164cid)
3.5L V6 (3496cc / 213cid)
Direct-fit bolt-on design: No cutting, welding, or fabrication required.
Uses OE-style hanger points: Ensures proper alignment and clearance.
Stainless steel body: Provides extended service life, especially in high-salt or high-moisture regions.
Not reversible: Must be installed in the correct orientation.
Inspect gaskets & hardware: Replace as necessary for a proper seal.
Professional installation recommended for best fitment and performance.
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).
