Which medium-duty chassis does Foundation build on?
Ford F-450 and F-550, Ram 5500, and Chevrolet 4500–6500. If you already own the chassis, we can usually build on it; we can also coordinate the chassis as part of the build.
Platform · Medium-duty trucks
Medium-Duty Composite Expedition Bodies
When a van or cutaway runs out of payload, clearance, or range, the same composite build steps up to a thicker 2.5-inch panel and a four-point Zero-Torsion subframe on a medium-duty chassis — Ford F-450/550, Ram 5500, or Chevrolet 4500–6500. It’s a full expedition cabover, custom-sized to the payload, range, and clearance a bigger trip or job demands.
At a glance
The Medium-Duty Expedition platform in brief
- Chassis
- Ford F-450/550 · Ram 5500 · Chevrolet 4500–6500
- Panel
- 2.5-inch composite panel, R17
- Subframe
- Four-point Zero-Torsion
- Cab-over
- Queen or king cabover, cab passthrough
- Sizing
- Custom to the chassis and build
- Build path
- We build and install (final-stage manufacturer)
Why buyers move beyond a van or cutaway
A medium-duty chassis brings a much higher payload ceiling, room for larger fuel and water, super-single wheels and serious ground clearance, and the frame strength to carry a bigger habitat off-road for years. If you’re building for full-time expedition travel, heavy systems, or a demanding commercial mission, the medium-duty cabover is where the platform goes.
The 2.5-inch panel and four-point subframe
The body steps up from the van’s 1.5-inch R11 panel to a thicker, higher-R (R17) 2.5-inch composite panel, mounted on a four-point Zero-Torsion subframe. On a longer, heavier body over a flexing medium-duty frame, the multi-point subframe manages the greater loads and torsion — letting the chassis articulate while the habitat stays square. It’s the same principle as the E-Series subframe, scaled up for the duty.
- Higher-R (R17) 2.5-inch composite panel — more insulation for four-season, off-grid use
- Four-point Zero-Torsion subframe for the longer, heavier body
- Queen or king cabover with a cab passthrough
- Super-single wheels and suspension upgrades as part of a full upfit
- Underbody storage and departure-angle bodywork sized to the chassis
Complete body installation, or interior upfit
On medium-duty trucks we build and install the full composite cabover as a final-stage manufacturer, custom-sized to your chassis and cab configuration. From there the interior is finished by you or your professional builder. If you already run an F-550, Ram 5500, or Chevrolet chassis, we can usually build on it.
Common questions
Medium-Duty Expedition — questions people ask
How is the medium-duty body different from the van bodies?
It uses a thicker 2.5-inch composite panel on a four-point Zero-Torsion subframe, with a queen or king cabover, and it is custom-sized rather than offered in fixed van lengths — because the payload, clearance, and range targets are higher.
Can I get a spec/quote for my chassis?
Yes — medium-duty builds are sized and quoted to your specific chassis and use. Tell us the truck and how you’ll use it and we’ll put together sizing and pricing.
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