Image coming soonWehrli 2004.5-2005 LLY Duramax 4" Cold Air Intake Kit with Air Box
Can I pick up my order or have it installed at your shop?
Can I pick up my order or have it installed at your shop?
Absolutely. We offer local pickup on most products and full professional installation at our shop in Washington, MO. Whether you just want to grab your parts or have our techs handle the install, we’ve got you covered. Give us a quick call at 636-429-7020 or message us to schedule a visit — we’ll make sure the parts are ready when you arrive.
How do I know if this part fits my vehicle?
How do I know if this part fits my vehicle?
Unsure if it’ll fit? No problem — that’s what we’re here for. Send us your vehicle’s year, make, and model, and we’ll verify fitment before you order. We can also point you toward compatible upgrades or supporting parts if needed.
What if I need to return a product or it’s defective?
What if I need to return a product or it’s defective?
Most unused items can be returned within 30 days in their original packaging. Some products are covered by a manufacturer’s warranty as well. If something arrives damaged or doesn’t meet your expectations, just let us know — we’ll help you get it replaced, refunded, or repaired. (Tracking updates are also emailed automatically once your order ships.)
What's the lead time on custom or fabricated parts?
What's the lead time on custom or fabricated parts?
Many of our parts are built to order — especially fabricated or performance components. These can take additional time to produce before shipping. Lead times vary by manufacturer and demand, but we’ll always keep you updated along the way. If you’re working on a tight schedule, reach out before ordering at 636-429-7020 and we’ll confirm current availability or estimated ship dates.
Swap the restrictive factory plastic airbox on your 2004.5-2005 Chevrolet Silverado / GMC Sierra 2500HD/3500HD 6.6L Duramax LLY for the Wehrli 4" Cold Air Intake Kit with Air Box (Manufacturer Part # WCF100191). Fabricated 14 gauge aluminum intake pipe, a sealed 10 gauge air box with a dry filter, and an Outerwears hydrophobic pre-filter cover. Bolt on, no tuning required.
Why Choose the Wehrli 4" Cold Air Intake Kit?
- 4" pipe in 14 gauge aluminum – large diameter with smooth aerodynamic bends in place of the factory plastic, which improves intake air velocity and volume.
- Cold air from the inner fender – the sealed box pulls cooler air than the factory arrangement, so intake temperatures drop.
- 10 gauge aluminum box and lid – real material instead of moulded plastic, and the lid element lifts off for a filter check without pulling the box.
- Dry filter with a hydrophobic pre-filter cover – the Outerwears cover keeps water and grit off the element, protecting the MAF sensor, turbo and engine airways.
- Sealed with an O-ring and T-bolt clamps – silicone boot, O-ring seal and stainless steel T-bolt clamps rather than factory clips.
- More sound – a noticeably more aggressive engine and turbo note under acceleration.
- Custom powder coat – finished in your choice of Wehrli's colors. Made in the USA.
Kit Includes
- 4" intake pipe, 14 gauge aluminum
- Air box and lid, 10 gauge aluminum sheet
- Dry air filter
- Outerwears pre-filter cover
- Silicone boot, stainless steel T-bolt clamps and O-ring seal
- Installation hardware
Installation Highlights
Installs easily with basic hand tools and needs no tuning — it bolts onto an otherwise stock truck. The removable air box lid keeps ongoing filter service to a couple of minutes.
Fits These Models
2004.5 and 2005 Chevrolet Silverado 2500HD/3500HD and GMC Sierra 2500HD/3500HD with the 6.6L Duramax LLY.
Specifications
- Intake pipe: 4" diameter, 14 gauge aluminum
- Air box and lid: 10 gauge aluminum sheet
- Filter: dry element with Outerwears hydrophobic pre-filter cover
- Shipping weight: 11.0 lbs
- Package dimensions: 12" W x 12" H x 32" L, ships in its own box
- Finish: custom powder coat, color selected above
- Made in the USA
Key Features at a Glance
- 4" fabricated aluminum intake - replaces the restrictive factory tube.
- 10 gauge sealed air box - no plastic, serviceable lid.
- Dry filter with Outerwears cover - protects the MAF sensor and turbo.
- No tuning required - bolt on to a stock truck.
- Basic hand tools - no drilling, no fabrication.
- Custom powder coat finish - pick your color above.
Notes
- Lead time varies by color. WCFab Red and WCFab Grey with the standard brushed tag are stocked and ship in 3-5 business days. All other colors are made to order on a 10-15 business day lead time.
- This is the standard intake kit. Wehrli's Stage 2 version for this truck adds a 4.8" turbo intake horn on top of what is here — call if you want the horn included.
FASS SKU: [ADD FASS SKU]
Manufacturer Part #: WCF100191
Questions? We’re Here to Help.
Have questions about upgrades for your 6.6L Duramax LLY? Contact FASS Motorsports and we’ll get you dialed:
Phone: 636-429-7020
Email: info@fassmotorsports.com
This part fits the following vehicles:
| Years | Make & Model |
|---|---|
| 2004 | Chevrolet Silverado 2500 |
| 2004–2005 | Chevrolet Silverado 3500 |
| 2004 | GMC Sierra 2500 |
| 2004–2005 | GMC Sierra 3500 |
| 2005 | Chevrolet Silverado 2500 HD |
| 2005 | GMC Sierra 2500 HD |
Fitment is listed by year, make and model. Some applications also depend on cab, bed, drivetrain or engine — if you are not sure, call 636-429-7020 or send us your vehicle details and we will confirm before you order.
