Wehrli 2004.5-2005 LLY Duramax 3" Passenger (Cold) Side Intercooler Pipe Kit
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.
Kill the boost leaks on your 2004.5-2005 Chevrolet Silverado / GMC Sierra 2500HD/3500HD 6.6L Duramax LLY with the Wehrli 3" Passenger (Cold) Side Intercooler Pipe Kit (Manufacturer Part # WCF100355). This one-piece, mandrel bent 14 gauge aluminum pipe replaces the 2.5" factory aluminum tube and the OEM clip ring that fails under boost. Bolts to a stock truck, no tuning and no other modifications required.
Why Choose the Wehrli 3" Passenger (Cold) Side Intercooler Pipe Kit?
- 3" replaces 2.5" – Wehrli measures this pipe flowing 56% better than the factory piece, with mandrel bends instead of the stock restrictions.
- One piece, not two – fewer joints between the intercooler and the Y-bridge means fewer places for pressure to escape.
- Clip ring deleted – the OEM clip ring design is replaced by a high quality silicone boot and stainless steel T-bolt clamps that actually hold boost.
- Straight boot connection at the intercooler – unlike the angled factory connection, which is a known leak point on the LLY.
- Keeps your OEM Y-bridge – compatible with the factory Y-bridge / cross over pipe, so this is a standalone upgrade, not the start of a chain.
- Better spool and throttle response – improved airflow between the turbo and the engine, and a weak point removed before it fails in a hard working truck.
- Custom powder coat – finished in your choice of Wehrli's colors, made in the USA.
Kit Includes
- 3" passenger (cold) side intercooler pipe, 14 gauge aluminum, one piece
- Silicone boots
- Stainless steel T-bolt clamps
Installation Highlights
Installs easily with basic hand tools. Fits a stock truck with no additional modifications, upgrades or tuning needed, and retains the factory Y-bridge / cross over pipe connection.
Fits These Models
2004, 2004.5 and 2005 Chevrolet Silverado 2500HD/3500HD and GMC Sierra 2500HD/3500HD with the 6.6L Duramax LLY.
Specifications
- Pipe diameter: 3" (replaces 2.5" factory pipe)
- Construction: 14 ga. mandrel bent aluminum, one piece
- Flow: 56% better than stock, per Wehrli
- Replaces GM part numbers: 15188720, 15188721, 15198168
- Shipping weight: 6.0 lbs
- Package dimensions: 32" W x 12" H x 12" L, ships in its own box
- Finish: custom powder coat, color selected above
- Made in the USA
Key Features at a Glance
- 3" one-piece pipe - upsizes the factory 2.5" restriction.
- Silicone boot and T-bolt clamps - replaces the leak-prone OEM clip ring.
- Straight intercooler connection - fixes the angled factory boot joint.
- OEM Y-bridge compatible - no other parts required.
- No tuning required - bolt on to a stock truck.
- Custom powder coat finish - pick your color above.
Notes
- ⚠ NOT COMPATIBLE WITH BANKS INTERCOOLERS. If you are running a Banks intercooler, this pipe will not fit.
- Lead time varies by color. WCFab Red, Candy Teal, Gloss White and Gloss Black are stocked and ship in 3-5 business days. All other colors are made to order on a 10-15 business day lead time.
- Pairs best with emissions compliant tuning and a drop-in turbocharger if you are chasing bigger gains.
FASS SKU: [ADD FASS SKU]
Manufacturer Part #: WCF100355
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.
