This Borla S-Type muffler (60679) replaces the Polyphonic Harmonizer behind the primary muffler in select Borla ATAK cat-back systems for the Chevrolet Silverado 1500 and GMC Sierra 1500 6.2L, dropping the tone to the quieter S-Type level. It is a 3.5in diameter direct-fit muffler built from premium T-304 stainless steel with CNC-accurate construction for maximum flow and power.
| Type | S-Type replacement muffler |
| Sound | S-Type (quieter than ATAK) |
| Diameter | 3.5in |
| Material | T-304 stainless steel |
| Use | Swaps into select Borla GM truck ATAK systems for S-Type sound |
| Warranty | Million-Mile Warranty |
Documents: Installation Instructions (PDF)
This part fits:
| Year | Make | Model | Submodel |
|---|---|---|---|
| 2020-2021 | Chevrolet | Silverado 1500 | Custom Trail Boss |
| 2019-2026 | Chevrolet | Silverado 1500 | High Country |
| 2020-2026 | Chevrolet | Silverado 1500 | LT Trail Boss |
| 2019-2026 | Chevrolet | Silverado 1500 | LTZ |
| 2020-2026 | Chevrolet | Silverado 1500 | RST |
| 2022-2026 | Chevrolet | Silverado 1500 | ZR2 |
| 2019-2026 | GMC | Sierra 1500 | AT4 |
| 2022-2026 | GMC | Sierra 1500 | AT4X |
| 2019-2026 | GMC | Sierra 1500 | Denali |
| 2022-2026 | GMC | Sierra 1500 | Denali Ultimate |
| 2019-2026 | GMC | Sierra 1500 | SLT |
