1. Chassis Cab:
* Purpose-built Chassis: For most aluminum box trucks, the manufacturer starts with a *chassis cab*. This is essentially a Chevy truck frame (or a frame from another manufacturer like Ford or Freightliner) with a cab, but *no* bed. The aluminum box body is then manufactured separately and *mounted* onto the chassis. This involves:
* Subframe: Often, a steel subframe is welded to the chassis rails. This provides a strong, level mounting surface for the box body.
* Bolting: The aluminum box is then bolted to the subframe using numerous high-strength bolts. These bolts are strategically placed to distribute the weight evenly.
* Welding: In some cases, welding might be used in addition to bolting, particularly for critical structural connections.
2. Conversion:
* Removing Existing Bed: If someone is converting a standard Chevy pickup truck into a box truck, the existing bed needs to be removed completely.
* Subframe/Mounting System: A custom subframe or mounting system is then usually fabricated and welded to the Chevy frame. This provides the necessary support for the aluminum box. The design and materials will be tailored to the specific weight and size of the box.
* Bolting/Welding: Similar to the chassis cab method, bolting and potentially welding secure the aluminum box body to the newly created mounting system.
Key Considerations:
* Weight Distribution: Proper weight distribution is crucial to avoid stressing the Chevy frame. This is a major consideration during the design and installation of the box body.
* Corrosion Prevention: Since aluminum and steel can react with each other, measures are taken to prevent corrosion. This often involves using corrosion-resistant fasteners, sealants, and coatings.
* Safety: The mounting needs to meet safety standards to ensure the box won't detach during driving.
In short, it's not a simple "bolt it on" process. It's a more involved procedure requiring expertise in chassis construction, welding, and weight distribution. The specifics will depend heavily on the size and weight of the aluminum box and the model of Chevy chassis being used.
