Kenworth T800 High Hood Conversion: Engineering, Cooling, and Customization Insights

[MikePhua]

Introduction to the T800 Hood Variants
The Kenworth T800 is a versatile workhorse in the heavy-duty trucking world, known for its adaptability across vocational applications. One of its defining features is the hood configuration—either the sloped hood for better visibility or the straight high hood for enhanced cooling and classic styling. Converting a sloped hood T800B to a high hood setup is a nuanced process that blends mechanical precision with aesthetic preference.
Terminology Notes

• High Hood: A taller, flatter hood design that accommodates larger radiators and offers a traditional look.
  
• Sloped Hood: A lower-profile hood that improves forward visibility, often preferred in urban or tight maneuvering environments.
  
• Radiator Core Support: The structural frame that holds the radiator in place; its dimensions affect hood compatibility.
  
• Mounting Points: Locations where the hood attaches to the chassis and hinges—critical for alignment and fit.
  
• 7CZ Flash: A Caterpillar ECM tuning file, often used to boost horsepower in CAT engines.
  

Conversion Feasibility and Technical Considerations
The conversion from a sloped hood to a high hood is technically feasible but requires careful planning. Key factors include:

• Radiator Compatibility
  Some believe the high hood uses a taller radiator for increased cooling capacity. However, field reports suggest that the radiator core may be the same, with only the tinwork (sheet metal) differing to accommodate the hood profile.
  
• Mounting Adjustments
  The hood hinges, latch points, and fender mounts may need repositioning. Measuring the radiator height and verifying mounting brackets is essential before sourcing parts.
  
• Cooling Requirements
  Trucks running high-output engines—such as a CAT 3406E with a 7CZ flash and marine cam—generate significant heat. A high hood allows for better airflow and larger radiators, which is crucial for engines pushing 725+ horsepower.
  

Real-World Examples and Anecdotes

• A trucker in Western Canada successfully converted a 2015 T800B to a high hood by modifying the radiator shroud and adjusting the mounting brackets. The cooling performance improved noticeably, especially during logging operations in mountainous terrain.
  
• Another operator running a 7CZ flash with an 800hp marine cam noted that even with a high-efficiency louvered fin and dimpled tube radiator, heat management was borderline. The high hood allowed for a larger surface area and better airflow, reducing engine temps under load.
  
• In a separate case, a T800 converted for show purposes featured a high hood paired with chrome accents and a custom grille. While not performance-driven, the aesthetic transformation drew attention at regional truck shows and highlighted the visual impact of the conversion.
  

Industry Trends and Historical Context
The high hood design harkens back to the classic Kenworth styling of the 1980s and 1990s, favored by long-haul drivers and vocational fleets in hot climates. As emissions regulations and engine outputs evolved, cooling demands increased, making the high hood more than just a stylistic choice.
In recent years, aftermarket suppliers have responded with fiberglass and aluminum high hood kits compatible with various T800 chassis configurations. These kits often include:

• Hood shell with grille cutouts
  
• Fender extensions
  
• Radiator support brackets
  
• Mounting hardware and hinge assemblies
  

Challenges and Recommendations

• Fitment Issues
  Not all T800 frames are identical. Mid-year changes and regional spec variations can affect compatibility. Always verify VIN-specific dimensions before ordering parts.
  
• Cost Considerations
  A full conversion can cost between $3,000–$6,000 depending on parts, labor, and paint. DIY installations are possible but require mechanical expertise and lifting equipment.
  
• Cooling vs. Visibility Trade-Off
  While the high hood improves cooling, it reduces forward visibility. Operators must weigh performance needs against safety and maneuverability.
  

Conclusion: Engineering Meets Identity
Converting a T800 to a high hood configuration is more than a mechanical upgrade—it’s a statement of purpose. Whether driven by cooling demands, aesthetic preference, or vocational necessity, the transformation reflects the truck’s evolving role. As one veteran driver put it, “The high hood isn’t just about airflow—it’s about attitude.”