HSP Diesel

HSP Billet Thermostat Housing and Pipe for 2001-2005 Duramax

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  • Regular price $403.75
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This product may have a lead time, please confirm with sales@dieselpartdeals.com if in a rush

The 040-HSP Or HSP Billet Thermostat Housing Kit for the 2001-2005 Chevrolet and GMC Duramax is an awesome piece of billet equipment!


Why Would you need an HSP Billet Thermostat Housing Kit?

Let’s start with the fact that the factory location and how tight things route inside the engine bay of a Duramax-powered Chevrolet and GMC truck. This makes things extremely difficult when you have to change to a different valley-based turbo that has no cooling provisions.


What does the HSP Billet Thermostat Housing Kit do differently?

First off the HSP Billet Thermostat Housing Kit is a billet thermostat housing and tube that eliminates the factory coolant hose that crosses over the driver’s side valve cover. What this does for you is it allows more room for aftermarket turbo systems and fuel components. Such as twin-turbo systems that need things moved especially when you are making your own, having the extra room in the first place makes all the difference. The HSP Billet Thermostat Housing Kit also allows you the extra room to run dual CP3 Kits and we all know that when we are trying to make the big power that comes with these add ons worrying about the room and worrying that your thermostat housing is going to work correctly.


What comes with the HSP Billet Thermostat Housing Kit?

  • (1) Thermostat Housing O-Ring
  • (3) M6 x 1.0 x 35mm Flange Bolts
  • (6) M6 Fender Washer
  • (3) M6 Nylon Lock Nuts
  • (4) M8 x 1.25-25mm Socket Cap bolt
  • (4) M6 x 1.0-18mm Socket Cap bolt
  • (1) 1.75" x 3" Straight Boot (437-RFAB)
  • (1) 1.75" x 90° Boot (433-RFAB)
  • (4) 1 3/4" Worm Gear Clamps (408-RFAB)


Special note

At this time HSP Diesel is making a running change in boot style. This means you will possibly get boots with no logos on them. Please know we are doing this to make sure we can continue to provide you with the high-quality parts you have gotten from HSP Diesel in the past.

What Does the HSP Billet Thermostat Housing Kit Fit?

  • LB7: 01-04 VIN Code 1
  • LLY: 04.5-05 VIN Code 2


How do people know the VIN code?

Engine code is dictated by the 8th character of the VIN number. The 10th character is the year of the truck.



  • CNC Machined Billet Aluminum thermostat upper housing
  • Allows for added room for aftermarket turbochargers
  • Easier access to fuel system components on drivers side valve cover
  • Powder-coated hard tube to improve the look of the engine bay
  • Allows room for dual CP3 pump kits
  • Multiple color options and custom options available
  • Makes room for unique and high powered turbo setups


Our Warranty


At HSP we believe in our products and we stand firmly behind every single one that leaves our facility. For years we have taken care of almost everything & anything that our customers had issues with, but we didn’t have a “set in stone” warranty. We have always gone above and beyond for our customers which set us apart from the rest. We will continue that same standard, but now we are taking things to the next level. Below you will be able to clearly read & understand our “No BS” warranty, its process, and the guidelines in which to follow.