Replace the Polyphonic Harmonizer behind the primary muffler in the BORLA® ATAK® system with muffler 60679 to attain the S-Type sound level (quieter than ATAK®). Built from premium T-304 stainless steel, superior to T-400 series knockoffs (such as 409), to give you the absolute best in performance and durability. Designed to provide maximum flow & power. Precision computer numerical control (CNC) manufacturing ensures an accurate fit. Best of all, BORLA® stands behind every direct fit muffler with a Million-Mile Warranty. Just what you’d expect from the world’s most experienced (and most winning) exhaust brand.
Installation InstructionsThis 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 |
Most items ship directly from authorized distributors. Lead times vary by brand and availability.
Returns are permitted within 30 days of receiving your order under specific conditions. For more information, view our Return & Refund Policy
Professional installation available at our Metro Atlanta facility. Contact us to schedule your build.

