Product Description
S&S Diesel LLY-400SAC-SET 400% Over Injector Set (New) — 2004.5–2005 GM Duramax 6.6L LLY
Built for serious competition power, this brand-new 400% over injector set uses SAC nozzles and OE-level build practices to deliver massive fuel flow with consistency. Each set is balanced and flow-matched for precise delivery, giving your LLY the headroom it needs for big turbo, big RPM builds.
Fitment
- 2004.5–2005 Chevrolet Silverado/Sierra 2500HD & 3500HD — 6.6L Duramax LLY.
- Direct LLY replacement set; intended for competition / high-output applications.
What’s Included
- (8) S&S Diesel Motorsport LLY Injectors — 400% Over (New)
- SAC-style nozzles, honed and matched
- Set balanced and flow-matched for uniform delivery
- Documentation / install notes
Recommended Supporting Parts
- Duramax Injectors / Nozzles (Category) — shop complementary injector hardware and alternatives.
- Shop All S&S Diesel at CPP — pumps, injectors, and fuel system components.
- GM Duramax Parts Hub — find supporting upgrades: lift pumps, fuel filtration, turbos, and more.
Important Notes
- Tuning & fuel system: Supporting fuel supply, air system, and custom calibration are required for 400% over injectors.
- Competition use: Extremely high flow; verify class rules and local regulations before purchase/installation.
FAQ
Do these fit all 2004 LLY trucks?
These are for mid-year 2004.5 through 2005 LLY applications. Confirm your VIN/build date and engine RPO is LLY before ordering.
Are these new or reman?
This part number is a brand-new set. (S&S also offers reman options on some sizes.)
Do I need tuning and other mods?
Yes. 400% over injectors require extensive supporting mods (lift pump, turbo(s), air/fuel system) and custom tuning.
What nozzle style is used?
SAC-style nozzles with S&S proprietary honing and tight flow-matching for consistency.
What kind of balancing/flow-matching is done?
Each set is matched to tight tolerances to ensure even cylinder-to-cylinder fueling under load.
