2005 GMC TopKick
C4500 Monroe 4×4

Monroe Truck Equipment is a Wisconsin-based upfitter that has been converting commercial chassis into specialty vehicles since 1958. Their C4500/C5500 pickup conversion takes the bare GMC TopKick (or Chevrolet Kodiak) cab-and-chassis — a medium-duty commercial platform — and transforms it into a fully functional pickup truck.

The conversion includes fabricating and installing a full pickup bed, integrating rear lighting, adding proper bumpers, and finishing the truck so it looks and functions like a factory-built pickup — but on a much heavier, more capable platform. The result is a truck with the towing and payload capacity of a commercial vehicle combined with the comfort and drivability of a personal-use pickup.

These conversions were never mass-produced. Each truck was built to order, making them inherently rare. The C4500 platform features a GVWR of 16,500 lbs, full air brakes (on some configurations), a frame rated for serious work, and the same proven Duramax/Allison powertrain found in the 2500HD and 3500HD — but in a chassis designed to handle significantly more weight and stress.

Because of their rarity, capability, and unique road presence, Monroe-converted TopKicks and Kodiaks have become highly collectible among truck enthusiasts. They offer something no factory half-ton or one-ton truck can: true medium-duty strength in a package you can drive every day.