Wehrli 2001-2005 LB7/LLY Duramax Top Outlet Billet Thermostat Housing and Upper Coolant 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.
Get the ugly black rubber radiator hose off the top of your 2001-2005 Chevrolet Silverado / GMC Sierra 2500HD/3500HD 6.6L Duramax LB7 and LLY with the Wehrli Top Outlet Billet Thermostat Housing and Upper Coolant Pipe Kit (Manufacturer Part # WCF100405). It replaces the OEM upper radiator hose that crosses the driver side valve cover, plus the factory coolant return pipe, and reroutes coolant up and forward straight off the thermostat to the radiator.
Why Choose the Wehrli Top Outlet Billet Thermostat Housing Kit?
- Room for a bigger turbo – taking the coolant plumbing off the top of the engine is what makes space for larger aftermarket chargers.
- Required for valley-mounted turbos – if you are running a race cover style or SXE charger in the valley, this kit is not optional, it is the clearance.
- Easier access to the driver side fuel system – the rerouted pipe opens up the components buried under the factory hose.
- CNC machined billet aluminum housing – the upper thermostat housing is machined, not cast, and carries the WCFab tag.
- 14 gauge pipe, not 16 – heavier wall than the common aftermarket gauge, so you can pull the T-bolt clamps tight without kinking or denting the tube and still get a leak-free boot seal.
- Later-model routing on an early truck – it lays the coolant path out the way GM did it from 2011 on, instead of over the top of the engine.
- Honest about what it is – Wehrli says it plainly: this is a cleanup and clearance part, not a horsepower part.
Kit Includes
- CNC machined billet aluminum thermostat upper housing
- Upper coolant pipe, 14 gauge aluminum
- Silicone boots
- Stainless steel T-bolt clamps
Fits These Models
2001, 2002, 2003, 2004, 2004.5 and 2005 Chevrolet Silverado 2500HD/3500HD and GMC Sierra 2500HD/3500HD with the 6.6L Duramax LB7 or LLY.
Specifications
- Thermostat upper housing: CNC machined billet aluminum
- Coolant pipe: 14 gauge aluminum
- Turbo compatibility: factory VGT style; required for race cover style or SXE turbochargers mounted in the valley
- Replaces GM part numbers: 15792832, 15198345
- Shipping weight: 4.0 lbs
- Package dimensions: 30" W x 10" H x 10" L, ships in its own box
- Finish: custom powder coat, color selected above, with WCFab tag
- Made in the USA
Key Features at a Glance
- Billet top outlet housing - reroutes coolant up and forward off the thermostat.
- Clears larger turbochargers - required for valley-mounted race cover or SXE setups.
- 14 ga. aluminum pipe - won't crush when you tighten the clamps.
- Deletes the OEM rubber hose - and the factory return pipe with it.
- Custom powder coat finish - pick your color above.
Notes
- ⚠ NOT COMPATIBLE WITH PPE DUAL FUELER SETUPS. It will work with WCFab Dual CP3 applications — the incompatibility is specific to PPE.
- Lead time varies by color. WCFab Red, Gloss Black and Gloss White are stocked and ship in 3-5 business days. All other colors are made to order on a 10-15 business day lead time.
- Wehrli offers a separate, simpler upper coolant pipe for this truck that replaces only the rubber hose and keeps the factory hard pipe. This kit is the full billet version that replaces both. Call if you are not sure which one you want.
FASS SKU: [ADD FASS SKU]
Manufacturer Part #: WCF100405
Questions? We’re Here to Help.
Have questions about upgrades for your 6.6L Duramax? 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 |
|---|---|
| 2001 | Chevrolet Silverado 2500 |
| 2001, 2005 | Chevrolet Silverado 3500 |
| 2001 | GMC Sierra 2500 |
| 2001, 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.
