Product Description
DIAMOND EYE K4127S is a 4.0" 409 stainless steel cat-back exhaust for 2006–2007 Chevy/GMC 2500/3500 HD 6.6L LBZ (all cab/bed lengths). This single passenger-side exit system includes a tuned muffler and uses mandrel bends for lower EGTs and a deeper tone, retaining factory-style hangers for a clean, bolt-on fit. Many kits also include the turbo direct pipe #321056 noted by Diamond Eye for this application.
Why it works: Free-flowing 4" 409SS tubing reduces backpressure and heat under load, improving throttle response and sound without drone when paired with the included muffler.
Fitment Details
- Platform: 2006–2007 Silverado/Sierra 2500HD/3500HD (LBZ Duramax, Classic body), all cab & bed lengths
- Configuration: 4" 409 stainless, cat-back, single side exit, muffler included
- Emissions Notes: Designed for 2006–2007 LBZ (pre-DPF); check local laws for on-road use
Cross-Reference / Alternatives (MBRP-only)
- MBRP GMCA424 3" Turbo Downpipe (LLY/LBZ/LMM) — popular pre-cat upgrade for quicker spool on 2004.5–2010 Duramax (incl. LBZ).
- MBRP GP010 4" Tail Pipe (01–07 LB7/LLY/LBZ) — direct replacement single-exit tail section.
- MBRP GMS9423 4" Front/adapter pipe (Regular Cab) — stainless adaptor for specific RC/LB setups.
- MBRP T5127 7" OD T304 Tip (5" inlet) — premium finish option for single-side outlet.
FAQs
WILL THIS FIT MY LBZ?
Yes—this kit targets 2006–2007 LBZ trucks (Classic body), all cab/bed lengths. Always match your VIN year/generation and check for prior exhaust mods.
DOES IT INCLUDE A MUFFLER?
Yes, K4127S is the single-exit cat-back with a muffler (stainless construction). A separate “-RP” variant denotes muffler-replacement/straight-pipe sections.
WHAT SOUND SHOULD I EXPECT?
Deeper, more assertive tone vs. stock with reduced restriction; civilized on the highway when installed with the included muffler.
Specifications
| Brand | Diamond Eye Performance |
|---|---|
| MPN | K4127S |
| Material | 409 Stainless Steel (4" mandrel-bent) |
| System Type | Cat-Back, Single Side Exit, Muffler Included |
| UPC | 841963121568 |
| GTIN | 00841963121568 (GTIN-14) / 841963121568 (GTIN-12) |
| Vehicle Fit | 2006–2007 Chevy/GMC 2500HD/3500HD 6.6L LBZ (Classic) |
| Shipping Weight | ~69 lb (typical for kit cartons) |
| Carton Dimensions | ~52" × 21" × 13" (typical) |
| Prop 65 | WARNING: Cancer and Reproductive Harm — www.P65Warnings.ca.gov |
Notes: Dimensions/weight reflect common retailer shipping specs for this series; actual packaging may vary slightly.
